Use buildozer to remove deprecated automanaged tags

pkg/util/async/BUILD

@@ -14,7 +14,6 @@ go_library(
         "bounded_frequency_runner.go",
         "runner.go",
     ],
-    tags = ["automanaged"],
     deps = [
         "//vendor/github.com/golang/glog:go_default_library",
         "//vendor/k8s.io/client-go/util/flowcontrol:go_default_library",
@@ -28,7 +27,6 @@ go_test(
         "runner_test.go",
     ],
     library = ":go_default_library",
-    tags = ["automanaged"],
 )
 
 filegroup(