Bump actions/checkout from 4.1.5 to 4.1.6 in the github-actions group

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


Updates `actions/checkout` from 4.1.5 to 4.1.6
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@44c2b7a...a5ac7e5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: github-actions
...

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

.github/workflows/dart.yaml

@@ -23,7 +23,7 @@ jobs:
     steps:
       # These are the latest versions of the github actions; dependabot will
       # send PRs to keep these up-to-date.
-      - uses: actions/checkout@44c2b7a8a4ea60a981eaca3cf939b5f4305c123b
+      - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
       - uses: dart-lang/setup-dart@f0ead981b4d9a35b37f30d36160575d60931ec30
         with:
           sdk: ${{ matrix.sdk }}
@@ -45,7 +45,7 @@ jobs:
         os: [ubuntu-latest, macos-latest, windows-latest]
         sdk: [dev, stable]
     steps:
-      - uses: actions/checkout@44c2b7a8a4ea60a981eaca3cf939b5f4305c123b
+      - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
       - uses: dart-lang/setup-dart@f0ead981b4d9a35b37f30d36160575d60931ec30
         with:
           sdk: ${{ matrix.sdk }}