Do not move m.room.related_groups state during room upgrade.

Author: clokep

synapse/api/constants.py

@@ -95,7 +95,6 @@ class EventTypes:
     Aliases: Final = "m.room.aliases"
     Redaction: Final = "m.room.redaction"
     ThirdPartyInvite: Final = "m.room.third_party_invite"
-    RelatedGroups: Final = "m.room.related_groups"
 
     RoomHistoryVisibility: Final = "m.room.history_visibility"
     CanonicalAlias: Final = "m.room.canonical_alias"

synapse/handlers/room.py

@@ -468,7 +468,6 @@ async def clone_existing_room(
             (EventTypes.RoomAvatar, ""),
             (EventTypes.RoomEncryption, ""),
             (EventTypes.ServerACL, ""),
-            (EventTypes.RelatedGroups, ""),
             (EventTypes.PowerLevels, ""),
         ]