Bump maven-pmd-plugin from 3.9.0 to 3.13.0 (#44)

Author: dependabot[bot]

pom.xml

@@ -827,7 +827,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-pmd-plugin</artifactId>
-                <version>3.9.0</version>
+                <version>3.13.0</version>
                 <configuration>
                     <linkXRef>true</linkXRef>
                     <analysisCache>false</analysisCache>