build(deps): Bump maven-plugin from 3.16 to 3.21 (#598)

Bumps [maven-plugin](https://github.com/jenkinsci/maven-plugin) from 3.16 to 3.21.
- [Release notes](https://github.com/jenkinsci/maven-plugin/releases)
- [Commits](jenkinsci/maven-plugin@maven-plugin-3.16...maven-plugin-3.21)

---
updated-dependencies:
- dependency-name: org.jenkins-ci.main:maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

pom.xml

@@ -101,7 +101,7 @@
     <jenkins-plugin-jacoco.version>3.3.2</jenkins-plugin-jacoco.version>
     <jenkins-plugin-jgiven.version>0.15.1</jenkins-plugin-jgiven.version>
     <jenkins-plugin-maven-invoker.version>2.4</jenkins-plugin-maven-invoker.version>
-    <jenkins-plugin-maven.version>3.16</jenkins-plugin-maven.version>
+    <jenkins-plugin-maven.version>3.21</jenkins-plugin-maven.version>
     <jenkins-plugin-mysql.version>8.0.16</jenkins-plugin-mysql.version>
     <jenkins-plugin-postgresql.version>42.3.3</jenkins-plugin-postgresql.version>
     <jenkins-plugin-script-security.version>1229.v4880b_b_e905a_6</jenkins-plugin-script-security.version>