Add EnumMeta.__new__ & EnumMeta.__call__ (#6572)

tests/stubtest_allowlists/py3_common.txt

@@ -83,8 +83,6 @@ distutils.command.bdist_packager  # It exists in docs as package name but not in
 distutils.version.Version._cmp  # class should have declared this
 distutils.version.Version.parse  # class should have declared this
 email.headerregistry.BaseHeader.max_count  # docs say subclasses should have this property
-enum.EnumMeta.__call__
-enum.EnumMeta.__new__
 http.HTTPStatus.description  # set in __new__
 http.HTTPStatus.phrase  # set in __new__
 http.client.HTTPConnection.response_class  # the actual type at runtime is abc.ABCMeta