Bump subosito/flutter-action from 2.8.0 to 2.10.0 (dart-lang/markdown#528)

Bumps [subosito/flutter-action](https://github.com/subosito/flutter-action) from 2.8.0 to 2.10.0.
- [Release notes](https://github.com/subosito/flutter-action/releases)
- [Commits](https://github.com/subosito/flutter-action/compare/dbf1fa04f4d2e52c33185153d06cdb5443aa189d...48cafc24713cca54bbe03cdc3a423187d413aafa)

---
updated-dependencies:
- dependency-name: subosito/flutter-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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