Remove legacy singular replication endpoint for resyncing remote user devices

[clokep]

I.e. all the code deprecated in #14716, this is pretty much:

• user_device_resync methods (I think? I don't see a reason to have these that just call the multi_ version)
• ReplicationUserDevicesResyncRestServlet

I think that's it. 👍

[clokep]

Since #14716 made it into the release branch I think we can pretty much do this whenever.

[tjay27]

in _multi_user_device_resync there is a use of ReplicationUserDevicesResyncRestServlet

synapse/synapse/handlers/device.py

Lines 935 to 938 in dd9e71d

	# Fall back to single requests
	result: Dict[str, Optional[JsonDict]] = {}
	for user_id in user_ids:
	result[user_id] = await self._user_device_resync_client(user_id=user_id)

Should we keep ReplicationUserDevicesResyncRestServlet ?

[clokep]

in _multi_user_device_resync there is a use of ReplicationUserDevicesResyncRestServlet

Should we keep ReplicationUserDevicesResyncRestServlet ?

No need to -- that's part of what we want to remove since it is the fallback path.

[khandelwalarvind26]

Hey, I'm a beginner contributor to synapse and found this issue in the good first issues section. Since the PR for this issue hasn't been merged yet, can I work on this issue?

[tjay27]

@khandelwalarvind26
yes, go ahead :D

[skmanoj322]

Hey wanted to make my Frist open source contribution so am I in a right place if yes can I start working on this problem