Bump dart-lang/setup-dart in the github-actions group (#329)

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


Updates `dart-lang/setup-dart` from 1.6.4 to 1.6.5
- [Release notes](https://github.com/dart-lang/setup-dart/releases)
- [Changelog](https://github.com/dart-lang/setup-dart/blob/main/CHANGELOG.md)
- [Commits](dart-lang/setup-dart@f0ead98...0a8a0fc)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
       # These are the latest versions of the github actions; dependabot will
       # send PRs to keep these up-to-date.
       - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332
-      - uses: dart-lang/setup-dart@f0ead981b4d9a35b37f30d36160575d60931ec30
+      - uses: dart-lang/setup-dart@0a8a0fc875eb934c15d08629302413c671d3f672
         with:
           sdk: ${{ matrix.sdk }}
       - run: dart pub get