Remove outgoing declaration in shadowRuntimeElements

It doubles the project.artifacts.add in configureShadowTask(..) which makes the artifact appear twice

Author: m8nmueller

src/main/groovy/com/github/jengelman/gradle/plugins/shadow/ShadowJavaPlugin.groovy

@@ -47,7 +47,6 @@ class ShadowJavaPlugin implements Plugin<Project> {
                     it.attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, project.objects.named(LibraryElements, LibraryElements.JAR))
                     it.attribute(Bundling.BUNDLING_ATTRIBUTE, project.objects.named(Bundling, Bundling.SHADOWED))
                 }
-                outgoing.artifact(project.tasks.named(SHADOW_JAR_TASK_NAME))
             }
         }