Upgrade to Maven Wrapper 3.9.1.

See #2520

Author: mp911de

.mvn/wrapper/maven-wrapper.properties

@@ -1,3 +1,3 @@
-#Mon Feb 20 12:02:21 CET 2023
+#Thu Apr 06 16:18:44 CEST 2023
 wrapperUrl=https\://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar
-distributionUrl=https\://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.0/apache-maven-3.9.0-bin.zip
+distributionUrl=https\://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.1/apache-maven-3.9.1-bin.zip