Bump org.apache.maven.plugins:maven-site-plugin from 3.12.1 to 3.20.0

Bumps [org.apache.maven.plugins:maven-site-plugin](https://github.com/apache/maven-site-plugin) from 3.12.1 to 3.20.0.
- [Release notes](https://github.com/apache/maven-site-plugin/releases)
- [Commits](apache/maven-site-plugin@maven-site-plugin-3.12.1...maven-site-plugin-3.20.0)

---
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]>

pom.xml

@@ -63,7 +63,7 @@
     <protoc-gen-grpc-java-plugin.version>1.47.0</protoc-gen-grpc-java-plugin.version>
     <puppycrawl-checkstyle.version>10.17.0</puppycrawl-checkstyle.version>
     <release-maven-plugin.version>3.1.1</release-maven-plugin.version>
-    <site-maven-plugin.version>3.12.1</site-maven-plugin.version>
+    <site-maven-plugin.version>3.20.0</site-maven-plugin.version>
     <source-maven-plugin.version>3.3.0</source-maven-plugin.version>
     <spotbug-maven-plugin.version>4.8.6.2</spotbug-maven-plugin.version>
     <spring-boot.version>3.3.2</spring-boot.version>