Gradle plugin: fix wrong external NotNull annotation

libraries/tools/kotlin-gradle-plugin/kotlinAnnotation/org/gradle/api/annotations.xml

@@ -8,9 +8,6 @@
         <val name="value" val="&quot;fun apply(p0 : T) : Unit&quot;" />
       </annotation>
     </item>
-    <item name='org.gradle.api.Project org.gradle.api.Project getParent()'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
     <item name="org.gradle.api.Project org.gradle.api.file.ConfigurableFileCollection files(java.lang.Object...)">
       <annotation name="org.jetbrains.annotations.NotNull" />
     </item>

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinPluginWrapper.kt

@@ -4,7 +4,6 @@ import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.api.artifacts.dsl.DependencyHandler
 import org.gradle.api.artifacts.ConfigurationContainer
-import org.gradle.api.artifacts.Dependency
 import org.gradle.api.specs.Spec
 import java.io.File
 import java.net.URL
@@ -79,7 +78,7 @@ abstract class KotlinBasePluginWrapper: Plugin<Project> {
                 return scriptHandler
             }
             log.debug("not found, switching to parent")
-            curProject = curProject.getParent()
+            curProject = curProject.getParent()!!
         }
         return null
     }