Bump dart-lang/setup-dart from 1.4.0 to 1.5.0 (dart-archive/source_span#95)

Bumps [dart-lang/setup-dart](https://github.com/dart-lang/setup-dart) from 1.4.0 to 1.5.0.
- [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@a57a6c0...d6a63da)

---
updated-dependencies:
- dependency-name: dart-lang/setup-dart
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pkgs/source_span/.github/workflows/test-package.yml

@@ -23,7 +23,7 @@ jobs:
         sdk: [dev]
     steps:
       - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c
-      - uses: dart-lang/setup-dart@a57a6c04cf7d4840e88432aad6281d1e125f0d46
+      - uses: dart-lang/setup-dart@d6a63dab3335f427404425de0fbfed4686d93c4f
         with:
           sdk: ${{ matrix.sdk }}
       - id: install
@@ -50,7 +50,7 @@ jobs:
         sdk: [2.18.0, dev]
     steps:
       - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c
-      - uses: dart-lang/setup-dart@a57a6c04cf7d4840e88432aad6281d1e125f0d46
+      - uses: dart-lang/setup-dart@d6a63dab3335f427404425de0fbfed4686d93c4f
         with:
           sdk: ${{ matrix.sdk }}
       - id: install