Ban obsolete dependency overrides (#290)

Fail the build if there are obsolete dependency management overrides.

Refer to plugin POM pull request:

* jenkinsci/plugin-pom#1381

Testing done:

* Confirmed that `mvn clean verify` passes

Author: MarkEWaite

pom.xml

@@ -50,6 +50,7 @@
     <spotless.check.skip>false</spotless.check.skip>
     <ban-junit4-imports.skip>false</ban-junit4-imports.skip>
     <ban-deprecated-stapler.skip>false</ban-deprecated-stapler.skip>
+    <banObsoleteDependencyOverrides.skip>false</banObsoleteDependencyOverrides.skip>
   </properties>
 
   <dependencies>