Build: Exclude plugin.xml from runtime classpath normalization

Version is written to the plugin.xml in every build so we exclude it to
improve caching.
Add test for kotlin plugin version to checkArtifacts.gradle.kts

build.gradle.kts

@@ -396,6 +396,7 @@ allprojects {
         runtimeClasspath {
             ignore("META-INF/MANIFEST.MF")
             ignore("META-INF/compiler.version")
+            ignore("META-INF/plugin.xml")
         }
     }