Bump codecov/codecov-action from 2.1.0 to 3
Bump codecov/codecov-action from 2.1.0 to 3

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 2.1.0 to 3.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/master/CHANGELOG.md)
- [Commits](https://github.com/codecov/codecov-action/compare/v2.1.0...v3)

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

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
google/mtail,google/mtail