Fix typo in socketserver docstring (GH-11252)

Fix typo in the docstring of `service_actions`.
serve_forver -> serve_forever
(cherry picked from commit 6ded898)

Co-authored-by: Christopher Hunt <[email protected]>

Author: miss-islington

Lib/socketserver.py

@@ -594,7 +594,7 @@ def handle_timeout(self):
         def service_actions(self):
             """Collect the zombie child processes regularly in the ForkingMixIn.
 
-            service_actions is called in the BaseServer's serve_forver loop.
+            service_actions is called in the BaseServer's serve_forever loop.
             """
             self.collect_children()