Bump codecov/codecov-action from 4.6.0 to 5.0.0 (#52)

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 4.6.0 to 5.0.0.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](codecov/codecov-action@b9fd7d1...9688725)

---
updated-dependencies:
- dependency-name: codecov/codecov-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/coverage.yml

@@ -23,7 +23,7 @@ jobs:
       - name: ./bin/flutter test --coverage
         run: pushd packages/flutter;../../bin/flutter test --coverage -j 1;popd
       - name: upload coverage
-        uses: codecov/codecov-action@b9fd7d16f6d7d1b5d2bec1a2887e65ceed900238
+        uses: codecov/codecov-action@968872560f81e7bdde9272853e65f2507c0eca7c
         with:
           files: packages/flutter/coverage/lcov.info
           verbose: true