Mention callbacks introduced in v1.46.0

According to #10548

Author: babolivier

docs/modules/password_auth_provider_callbacks.md

@@ -8,6 +8,8 @@ registered by using the Module API's `register_password_auth_provider_callbacks`
 
 ### `auth_checkers`
 
+_First introduced in Synapse v1.46.0_
+
 ```
  auth_checkers: Dict[Tuple[str,Tuple], Callable]
 ```
@@ -55,6 +57,8 @@ authentication fails.
 
 ### `check_3pid_auth`
 
+_First introduced in Synapse v1.46.0_
+
 ```python
 async def check_3pid_auth(
     medium: str, 
@@ -86,6 +90,8 @@ the authentication is denied.
 
 ### `on_logged_out`
 
+_First introduced in Synapse v1.46.0_
+
 ```python
 async def on_logged_out(
     user_id: str,