Bump pmdVersion from 6.55.0 to 7.0.0 (#1298)

pom.xml

@@ -52,7 +52,7 @@
     <!-- Plugin intentionally does not deliver javadoc. -->
     <!-- No API's intended to be used, none should be called from outside. -->
     <maven.javadoc.skip>true</maven.javadoc.skip>
-    <pmdVersion>6.55.0</pmdVersion>
+    <pmdVersion>7.0.0</pmdVersion>
     <spotbugs.effort>Max</spotbugs.effort>
     <spotbugs.threshold>Low</spotbugs.threshold>
     <spotless.check.skip>false</spotless.check.skip>
@@ -100,18 +100,6 @@
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-pmd-plugin</artifactId>
           <version>3.21.2</version>
-          <dependencies>
-            <dependency>
-              <groupId>net.sourceforge.pmd</groupId>
-              <artifactId>pmd-core</artifactId>
-              <version>${pmdVersion}</version>
-            </dependency>
-            <dependency>
-              <groupId>net.sourceforge.pmd</groupId>
-              <artifactId>pmd-java</artifactId>
-              <version>${pmdVersion}</version>
-            </dependency>
-          </dependencies>
         </plugin>
       </plugins>
     </pluginManagement>