Upgrade Checkstyle 10.6.0 -> 10.7.0

[Picnic-Bot]

This PR contains the following updates:

Package	Type	Update	Change
com.puppycrawl.tools:checkstyle (source)	build	minor	10.6.0 -> 10.7.0

---

• If you want to rebase/retry this PR, check this box

[Picnic-Bot]

Suggested commit message:

Upgrade Checkstyle 10.6.0 -> 10.7.0 (#486)

See:
- https://checkstyle.sourceforge.io/releasenotes.html
- https://github.com/checkstyle/checkstyle/releases/tag/checkstyle-10.7.0
- https://github.com/checkstyle/checkstyle/compare/checkstyle-10.6.0...checkstyle-10.7.0

[github-actions]

Looks good. No mutations were possible for these changes.
Mutation testing report by Pitest. Review any surviving mutants by inspecting the line comments under Files changed.