Fix GitDownloadTask fails on windows

Required for KTI-1553

kotlin-native/build-tools/src/main/kotlin/org/jetbrains/kotlin/testing/native/GitDownloadTask.kt

@@ -109,6 +109,6 @@ abstract class GitDownloadTask @Inject constructor(
         }
 
         // Delete the .git directory of the cloned repo to avoid adding it to IDEA's VCS roots.
-        fileOperations.delete(outputDirectory.dir(".git"))
+        outputDirectory.dir(".git").get().asFile.deleteRecursively()
     }
 }