Bump com.puppycrawl.tools:checkstyle from 10.20.2 to 10.21.0

Bumps [com.puppycrawl.tools:checkstyle](https://github.com/checkstyle/checkstyle) from 10.20.2 to 10.21.0.
- [Release notes](https://github.com/checkstyle/checkstyle/releases)
- [Commits](checkstyle/checkstyle@checkstyle-10.20.2...checkstyle-10.21.0)

---
updated-dependencies:
- dependency-name: com.puppycrawl.tools:checkstyle
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

airbase/pom.xml

@@ -201,7 +201,7 @@
         <dep.asm.version>9.7.1</dep.asm.version>
         <dep.assertj-core.version>3.26.3</dep.assertj-core.version>
         <dep.byte-buddy.version>1.15.10</dep.byte-buddy.version>
-        <dep.checkstyle.version>10.20.2</dep.checkstyle.version>
+        <dep.checkstyle.version>10.21.0</dep.checkstyle.version>
         <dep.errorprone.version>2.36.0</dep.errorprone.version>
         <dep.guava.version>33.3.1-jre</dep.guava.version>
         <dep.guice.version>7.0.0</dep.guice.version>