build(deps): bump maven-site-plugin from 4.0.0-M8 to 4.0.0-M9

Bumps [maven-site-plugin](https://github.com/apache/maven-site-plugin) from 4.0.0-M8 to 4.0.0-M9.
- [Release notes](https://github.com/apache/maven-site-plugin/releases)
- [Commits](apache/maven-site-plugin@maven-site-plugin-4.0.0-M8...maven-site-plugin-4.0.0-M9)

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

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

pom.xml

@@ -824,7 +824,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-site-plugin</artifactId>
-                <version>4.0.0-M8</version>
+                <version>4.0.0-M9</version>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -918,7 +918,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-site-plugin</artifactId>
-                    <version>4.0.0-M8</version>
+                    <version>4.0.0-M9</version>
                 </plugin>
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>