Set room version 8 as recommended for restricted rooms.

And enable room capabilities (MSC3244) by default.

synapse/api/room_versions.py

@@ -293,7 +293,7 @@ class RoomVersionCapability:
         ),
         RoomVersionCapability(
             "restricted",
-            None,
+            RoomVersions.V8,
             lambda room_version: room_version.msc3083_join_rules,
         ),
     )

synapse/config/experimental.py

@@ -37,4 +37,4 @@ def read_config(self, config: JsonDict, **kwargs):
         self.msc2285_enabled: bool = experimental.get("msc2285_enabled", False)
 
         # MSC3244 (room version capabilities)
-        self.msc3244_enabled: bool = experimental.get("msc3244_enabled", False)
+        self.msc3244_enabled: bool = experimental.get("msc3244_enabled", True)