[jnigen] Bump coverallsapp/github-action from 2.0.0 to 2.1.2 (https://github.com/dart-lang/jnigen/issues/269)

Bumps [coverallsapp/github-action](https://github.com/coverallsapp/github-action) from 2.0.0 to 2.1.2.
- [Release notes](https://github.com/coverallsapp/github-action/releases)
- [Commits](https://github.com/coverallsapp/github-action/compare/67662d24394fd74bffcf7b462d1b432814159afd...f350da2c033043742f89e8c0b7b5145a1616da6d)

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

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