Update dependency org.apache.maven.plugins:maven-source-plugin to v3.4.0

Author: renovate[bot]

pom.xml

@@ -27,7 +27,7 @@
     <gpg.useagent>true</gpg.useagent>
 
     <plugin.version.clean>2.6</plugin.version.clean>
-    <plugin.version.source>3.3.1</plugin.version.source>
+    <plugin.version.source>3.4.0</plugin.version.source>
     <plugin.version.compiler>3.14.0</plugin.version.compiler>
     <plugin.version.jar>2.5</plugin.version.jar>
     <plugin.version.javadoc>3.10.0</plugin.version.javadoc>