Add none language strings to code blocks. (#146154)

Part 2 from https://github.com/flutter/flutter/pull/146085
In preparation to add the lint
`missing_code_block_language_in_doc_comment`, added `none` info strings
to a bunch of fenced code blocks that have miscellaneous text or output
text.

Related to issue: https://github.com/dart-lang/linter/issues/4904

## Pre-launch Checklist

- [X] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [X] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [X] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [X] I signed the [CLA].
- [X] I listed at least one issue that this PR fixes in the description
above.
- [X] I updated/added relevant documentation (doc comments with `///`).
- [X] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [X] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/wiki/Tree-hygiene#overview
[Tree Hygiene]: https://github.com/flutter/flutter/wiki/Tree-hygiene
[test-exempt]:
https://github.com/flutter/flutter/wiki/Tree-hygiene#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/wiki/Tree-hygiene#handling-breaking-changes
[Discord]: https://github.com/flutter/flutter/wiki/Chat
[Data Driven Fixes]:
https://github.com/flutter/flutter/wiki/Data-driven-Fixes

dev/bots/test/analyze-snippet-code-test-input/known_broken_documentation.dart

@@ -162,7 +162,7 @@
 /// }
 /// ```
 ///
-/// ```
+/// ```none
 /// error (something about backticks)
 /// this must be the last error, since it aborts parsing of this file
 /// ```

dev/bots/test/analyze_snippet_code_test.dart

@@ -25,7 +25,7 @@ const List<String> expectedMainErrors = <String>[
   'dev/bots/test/analyze-snippet-code-test-input/known_broken_documentation.dart:153:10: (stateful widget) (annotate_overrides)',
   'dev/bots/test/analyze-snippet-code-test-input/known_broken_documentation.dart:153:10: (stateful widget) (must_call_super)',
   'dev/bots/test/analyze-snippet-code-test-input/known_broken_documentation.dart:161:7: (top-level declaration) (undefined_identifier)',
-  'dev/bots/test/analyze-snippet-code-test-input/known_broken_documentation.dart:165: Found "```" in code but it did not match RegExp: pattern=^ */// *```dart\$ flags= so something is wrong. Line was: "/// ```"',
+  'dev/bots/test/analyze-snippet-code-test-input/known_broken_documentation.dart:165: Found "```" in code but it did not match RegExp: pattern=^ */// *```dart\$ flags= so something is wrong. Line was: "/// ```none"',
   'dev/bots/test/analyze-snippet-code-test-input/short_but_still_broken.dart:9:12: (statement) (invalid_assignment)',
   'dev/bots/test/analyze-snippet-code-test-input/short_but_still_broken.dart:18:4: Empty ```dart block in snippet code.',
 ];

dev/conductor/core/lib/src/git.dart

@@ -93,7 +93,7 @@ enum GitExceptionType {
   ///
   /// Example output:
   ///
-  /// ```
+  /// ```none
   /// To github.com:user/engine.git
   ///
   ///  ! [rejected]            HEAD -> cherrypicks-flutter-2.8-candidate.3 (non-fast-forward)

dev/tools/gen_keycodes/lib/physical_key_data.dart

@@ -80,7 +80,7 @@ class PhysicalKeyData {
   ///
   /// Lines in this file look like this (without the ///):
   ///
-  /// ```
+  /// ```none
   /// key 100   ALT_RIGHT
   /// # key 101 "KEY_LINEFEED"
   /// key 477   F12               FUNCTION

dev/tools/localization/localizations_utils.dart

@@ -395,7 +395,7 @@ class $classNamePrefix$camelCaseName extends $superClass {''';
 
 /// Return the input string as a Dart-parseable string.
 ///
-/// ```
+/// ```none
 /// foo => 'foo'
 /// foo "bar" => 'foo "bar"'
 /// foo 'bar' => "foo 'bar'"
@@ -407,7 +407,7 @@ class $classNamePrefix$camelCaseName extends $superClass {''';
 /// in JSON files are escaped. For example, the backspace character (\b)
 /// has to be properly escaped by this function so that the generated
 /// Dart code correctly represents this character:
-/// ```
+/// ```none
 /// foo\bar => 'foo\\bar'
 /// foo\nbar => 'foo\\nbar'
 /// foo\\nbar => 'foo\\\\nbar'

packages/flutter_tools/lib/src/android/android_device.dart

@@ -877,7 +877,7 @@ Map<String, String> parseAdbDeviceProperties(String str) {
 ///
 /// Example output:
 ///
-/// ```
+/// ```none
 /// Applications Memory Usage (in Kilobytes):
 /// Uptime: 441088659 Realtime: 521464097
 ///

packages/flutter_tools/lib/src/asset.dart

@@ -853,7 +853,7 @@ class ManifestAssetBundle implements AssetBundle {
   /// - assets/bar
   ///
   /// This will return:
-  /// ```
+  /// ```none
   /// {
   ///   asset: packages/test_package/assets/foo: [
   ///     asset: packages/test_package/assets/foo,

packages/flutter_tools/lib/src/base/utils.dart

@@ -210,7 +210,7 @@ const int kMinColumnWidth = 10;
 /// ```
 ///
 /// yields:
-/// ```
+/// ```none
 ///   Usage: app main_command <subcommand>
 ///          [arguments]
 /// ```

packages/flutter_tools/lib/src/commands/update_packages.dart

@@ -1195,7 +1195,7 @@ class PubspecHeader extends PubspecLine {
   ///
   /// The value of this field extracted from the following line is "version".
   ///
-  /// ```
+  /// ```none
   /// version: 0.16.5
   /// ```
   final String? name;
@@ -1207,7 +1207,7 @@ class PubspecHeader extends PubspecLine {
   ///
   /// The value of this field extracted from the following line is "0.16.5".
   ///
-  /// ```
+  /// ```none
   /// version: 0.16.5
   /// ```
   final String? value;
@@ -1565,7 +1565,7 @@ class PubDependencyTree {
   ///
   /// That output is of this form:
   ///
-  /// ```
+  /// ```none
   /// package_name 0.0.0
   ///
   /// dependencies:

packages/flutter_tools/lib/src/localizations/localizations_utils.dart

@@ -228,7 +228,7 @@ String describeLocale(String tag) {
 
 /// Return the input string as a Dart-parsable string.
 ///
-/// ```
+/// ```none
 /// foo => 'foo'
 /// foo "bar" => 'foo "bar"'
 /// foo 'bar' => "foo 'bar'"
@@ -240,7 +240,7 @@ String describeLocale(String tag) {
 /// in JSON files are escaped. For example, the backspace character (\b)
 /// has to be properly escaped by this function so that the generated
 /// Dart code correctly represents this character:
-/// ```
+/// ```none
 /// foo\bar => 'foo\\bar'
 /// foo\nbar => 'foo\\nbar'
 /// foo\\nbar => 'foo\\\\nbar'

packages/flutter_tools/lib/src/macos/build_macos.dart

@@ -30,7 +30,7 @@ import 'migrations/remove_macos_framework_link_and_embedding_migration.dart';
 /// Passing this regexp to trace moves the stdout output to stderr.
 ///
 /// Filter out xcodebuild logging unrelated to macOS builds:
-/// ```
+/// ```none
 /// xcodebuild[2096:1927385] Requested but did not find extension point with identifier Xcode.IDEKit.ExtensionPointIdentifierToBundleIdentifier for extension Xcode.DebuggerFoundation.AppExtensionToBundleIdentifierMap.watchOS of plug-in com.apple.dt.IDEWatchSupportCore
 ///
 /// note: Using new build system

packages/flutter_tools/test/src/common.dart

@@ -264,7 +264,7 @@ class _NoContext implements AppContext {
 ///
 /// Example use:
 ///
-/// ```
+/// ```dart
 /// void main() {
 ///   var handler = FileExceptionHandler();
 ///   var fs = MemoryFileSystem(opHandle: handler.opHandle);

packages/fuchsia_remote_debug_protocol/lib/src/fuchsia_remote_connection.dart

@@ -182,7 +182,7 @@ class FuchsiaRemoteConnection {
   /// is expected to contain the interface as well (in the event that it is
   /// link-local), like the following:
   ///
-  /// ```
+  /// ```none
   /// fe80::1%eth0
   /// ```
   ///