Upgrade to Maven Wrapper 3.9.16.

See #2136

Author: mp911de

.mvn/wrapper/maven-wrapper.properties

@@ -1,2 +1,2 @@
-#Thu Jul 17 14:00:56 CEST 2025
-distributionUrl=https\://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.11/apache-maven-3.9.11-bin.zip
+#Tue Jun 02 15:00:45 CEST 2026
+distributionUrl=https\://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.16/apache-maven-3.9.16-bin.zip