Bump actions/checkout from 5 to 6 in the all-github-actions group

Bumps the all-github-actions group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `actions/checkout` from 5 to 6
- [Release notes](https://github.com/actions/checkout/releases)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: all-github-actions
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/content-aware-hash.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Generate Hash
         run: |

.github/workflows/coverage.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ github.repository == 'flutter/flutter' }}
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd
       - name: ./bin/flutter test --coverage
         run: pushd packages/flutter;../../bin/flutter test --coverage -j 1;popd
       - name: upload coverage

.github/workflows/easy-cp.yml

@@ -44,7 +44,7 @@ jobs:
         run: |
           echo "COMMIT_SHA=$(echo ${{ github.event.pull_request.merge_commit_sha }})" >> $GITHUB_ENV
       - name: Checkout Flutter Repo
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd
         with:
           repository: flutteractionsbot/flutter
           path: flutter

.github/workflows/files-changed.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Fetch base commit and origin/master
         # Fetch what to compare the commit against

.github/workflows/merge-changelog.yml

@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Setup Repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: ${{ github.repository }}
           ref: master

.github/workflows/tool-test-general.yml

@@ -22,7 +22,7 @@ jobs:
 
     steps:
       # Note: we must check out the tree for the composite action to be available
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ./.github/actions/composite-flutter-setup
 
       - name: Tool Test