chore(deps): bump org.apache.maven.plugins:maven-site-plugin

Bumps [org.apache.maven.plugins:maven-site-plugin](https://github.com/apache/maven-site-plugin) from 3.20.0 to 3.21.0.
- [Release notes](https://github.com/apache/maven-site-plugin/releases)
- [Commits](apache/maven-site-plugin@maven-site-plugin-3.20.0...maven-site-plugin-3.21.0)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-site-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -118,7 +118,7 @@
         <plugin.javadoc.version>3.10.1</plugin.javadoc.version>
         <plugin.checkstyle.version>3.6.0</plugin.checkstyle.version>
         <plugin.jacoco.version>0.8.12</plugin.jacoco.version>
-        <plugin.site.version>3.20.0</plugin.site.version>
+        <plugin.site.version>3.21.0</plugin.site.version>
         <plugin.scala.version>4.9.2</plugin.scala.version>
 
         <pekko.version>1.1.2</pekko.version>