Delete an unused (manual) workflow, added missing copyright headers. (#162050)

Just TLC while working on something related.

.github/workflows/files-changed.yml

@@ -1,3 +1,7 @@
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
 name: Generate Changed Files JSON
 
 on:

.github/workflows/lock.yaml

@@ -1,3 +1,7 @@
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
 # Configuration for Lock Threads - https://github.com/dessant/lock-threads
 
 name: 'Lock Threads'

.github/workflows/minimal.yml

@@ -1,44 +0,0 @@
-# Copyright 2023 The Flutter Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-name: Minimal workflow to test github action token
-
-on:
-  workflow_dispatch
-
-permissions: write-all
-
-jobs:
-  minimal_token_test:
-    name: minimal_token_test
-    runs-on: ubuntu-latest
-    permissions:
-      contents: write
-      pull-requests: write
-    steps:
-      - name: Checkout Flutter Repo
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-        with:
-          repository: flutter/flutter
-          token: ${{ github.token }}
-          path: flutter
-          ref: master
-          fetch-depth: 0
-      - name: Write a random file
-        run: |
-          cd flutter
-          touch empty.json
-      - name: Create Pull Request
-        uses: peter-evans/create-pull-request@67ccf781d68cd99b580ae25a5c18a1cc84ffff1f
-        with:
-          path: flutter
-          commit-message: blah
-          committer: GitHub <noreply@github.com>
-          token: ${{ secrets.FLUTTERACTIONSBOT_CP_TOKEN }}
-          labels: |
-            cp: review
-          title: '[github actions] testing purposes'
-          reviewers:
-            - christopherfujino
-            - jmagman

.github/workflows/no-response.yaml

@@ -1,3 +1,7 @@
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
 name: No Response
 
 # Both `issue_comment` and `scheduled` event types are required for this Action