Clean up no-untyped-def #46

Change-Id: Ieb56a1f986fe68df735aada5014cb6f3f959e02c

Author: LarsMichelsen

cmk/post_rename_site/registry.py

@@ -3,7 +3,6 @@
 # This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
 # conditions defined in the file COPYING, which is part of this source code package.
 
-# mypy: disable-error-code="no-untyped-def"
 
 from collections.abc import Callable
 from logging import Logger
@@ -45,7 +44,7 @@ def run(self, old_site_id: SiteId, new_site_id: SiteId) -> None:
 
 
 class RenameActionRegistry(Registry[RenameAction]):
-    def plugin_name(self, instance):
+    def plugin_name(self, instance: RenameAction) -> str:
         return instance.name