nixos/treewide: Move rename.nix imports to their respective modules

A centralized list for these renames is not good because:
- It breaks disabledModules for modules that have a rename defined
- Adding/removing renames for a module means having to find them in the
central file
- Merge conflicts due to multiple people editing the central file

nixos/modules/services/mail/rspamd.nix

@@ -220,7 +220,6 @@ let
 in
 
 {
-
   ###### interface
 
   options = {
@@ -414,5 +413,6 @@ in
 	     "Socket activation never worked correctly and could at this time not be fixed and so was removed")
     (mkRenamedOptionModule [ "services" "rspamd" "bindSocket" ] [ "services" "rspamd" "workers" "normal" "bindSockets" ])
     (mkRenamedOptionModule [ "services" "rspamd" "bindUISocket" ] [ "services" "rspamd" "workers" "controller" "bindSockets" ])
+    (mkRemovedOptionModule [ "services" "rmilter" ] "Use services.rspamd.* instead to set up milter service")
   ];
 }