Bump checker-qual from 3.20.0 to 3.21.0 (#343)
Bump checker-qual from 3.20.0 to 3.21.0 (#343)

Bumps [checker-qual](https://github.com/typetools/checker-framework) from 3.20.0 to 3.21.0.
- [Release notes](https://github.com/typetools/checker-framework/releases)
- [Changelog](https://github.com/typetools/checker-framework/blob/master/docs/CHANGELOG.md)
- [Commits](https://github.com/typetools/checker-framework/compare/checker-framework-3.20.0...checker-framework-3.21.0)

---
updated-dependencies:
- dependency-name: org.checkerframework:checker-qual
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
Pante/Karus-Commons