Merge tag 'v1.53.0rc1' into develop

Synapse 1.53.0rc1 (2022-02-15)
==============================

Features
--------

- Add experimental support for sending to-device messages to application services, as specified by [MSC2409](matrix-org/matrix-spec-proposals#2409). ([\#11215](#11215), [\#11966](#11966))
- Remove account data (including client config, push rules and ignored users) upon user deactivation. ([\#11655](#11655))
- Experimental support for [MSC3666](matrix-org/matrix-spec-proposals#3666): including bundled aggregations in server side search results. ([\#11837](#11837))
- Enable cache time-based expiry by default. The `expiry_time` config flag has been superseded by `expire_caches` and `cache_entry_ttl`. ([\#11849](#11849))
- Add a callback to allow modules to allow or forbid a 3PID (email address, phone number) from being associated to a local account. ([\#11854](#11854))
- Stabilize support and remove unstable endpoints for [MSC3231](matrix-org/matrix-spec-proposals#3231). Clients must switch to the stable identifier and endpoint. See the [upgrade notes](https://matrix-org.github.io/synapse/develop/upgrade#stablisation-of-msc3231) for more information. ([\#11867](#11867))
- Allow modules to retrieve the current instance's server name and worker name. ([\#11868](#11868))
- Use a dedicated configurable rate limiter for 3PID invites. ([\#11892](#11892))
- Support the stable API endpoint for [MSC3283](matrix-org/matrix-spec-proposals#3283): new settings in `/capabilities` endpoint. ([\#11933](#11933), [\#11989](#11989))
- Support the `dir` parameter on the `/relations` endpoint, per [MSC3715](matrix-org/matrix-spec-proposals#3715). ([\#11941](#11941))
- Experimental implementation of [MSC3706](matrix-org/matrix-spec-proposals#3706): extensions to `/send_join` to support reduced response size. ([\#11967](#11967))

Bugfixes
--------

- Fix [MSC2716](matrix-org/matrix-spec-proposals#2716) historical messages backfilling in random order on remote homeservers. ([\#11114](#11114))
- Fix a bug introduced in Synapse 1.51.0 where incoming federation transactions containing at least one EDU would be dropped if debug logging was enabled for `synapse.8631_debug`. ([\#11890](#11890))
- Fix a long-standing bug where some unknown endpoints would return HTML error pages instead of JSON `M_UNRECOGNIZED` errors. ([\#11930](#11930))
- Implement an allow list of content types for which we will attempt to preview a URL. This prevents Synapse from making useless longer-lived connections to streaming media servers. ([\#11936](#11936))
- Fix a long-standing bug where pagination tokens from `/sync` and `/messages` could not be provided to the `/relations` API. ([\#11952](#11952))
- Require that modules register their callbacks using keyword arguments. ([\#11975](#11975))
- Fix a long-standing bug where `M_WRONG_ROOM_KEYS_VERSION` errors would not include the specced `current_version` field. ([\#11988](#11988))

Improved Documentation
----------------------

- Fix typo in User Admin API: unpind -> unbind. ([\#11859](#11859))
- Document images returned by the User List Media Admin API can include those generated by URL previews. ([\#11862](#11862))
- Remove outdated MSC1711 FAQ document. ([\#11907](#11907))
- Correct the structured logging configuration example. Contributed by Brad Jones. ([\#11946](#11946))
- Add information on the Synapse release cycle. ([\#11954](#11954))
- Fix broken link in the README to the admin API for password reset. ([\#11955](#11955))

Deprecations and Removals
-------------------------

- Drop support for `webclient` listeners and configuring `web_client_location` to a non-HTTP(S) URL. Deprecated configurations are a configuration error. ([\#11895](#11895))
- Remove deprecated `user_may_create_room_with_invites` spam checker callback. See the [upgrade notes](https://matrix-org.github.io/synapse/latest/upgrade.html#removal-of-user_may_create_room_with_invites) for more information. ([\#11950](#11950))
- No longer build `.deb` packages for Ubuntu 21.04 Hirsute Hippo, which has now EOLed. ([\#11961](#11961))

Internal Changes
----------------

- Enhance user registration test helpers to make them more useful for tests involving application services and devices. ([\#11615](#11615), [\#11616](#11616))
- Improve performance when fetching bundled aggregations for multiple events. ([\#11660](#11660), [\#11752](#11752))
- Fix type errors introduced by new annotations in the Prometheus Client library. ([\#11832](#11832))
- Add missing type hints to replication code. ([\#11856](#11856), [\#11938](#11938))
- Ensure that `opentracing` scopes are activated and closed at the right time. ([\#11869](#11869))
- Improve opentracing for incoming federation requests. ([\#11870](#11870))
- Improve internal docstrings in `synapse.util.caches`. ([\#11876](#11876))
- Do not needlessly clear the `get_users_in_room` and `get_users_in_room_with_profiles` caches when any room state changes. ([\#11878](#11878))
- Convert `ApplicationServiceTestCase` to use `simple_async_mock`. ([\#11880](#11880))
- Remove experimental changes to the default push rules which were introduced in Synapse 1.19.0 but never enabled. ([\#11884](#11884))
- Disable coverage calculation for olddeps build. ([\#11888](#11888))
- Preparation to support sending device list updates to application services. ([\#11905](#11905))
- Add a test that checks users receive their own device list updates down `/sync`. ([\#11909](#11909))
- Run Complement tests sequentially. ([\#11910](#11910))
- Various refactors to the application service notifier code. ([\#11911](#11911), [\#11912](#11912))
- Tests: replace mocked `Authenticator` with the real thing. ([\#11913](#11913))
- Various refactors to the typing notifications code. ([\#11914](#11914))
- Use the proper type for the `Content-Length` header in the `UploadResource`. ([\#11927](#11927))
- Remove an unnecessary ignoring of type hints due to fixes in upstream packages. ([\#11939](#11939))
- Add missing type hints. ([\#11953](#11953))
- Fix an import cycle in `synapse.event_auth`. ([\#11965](#11965))
- Unpin `frozendict` but exclude the known bad version 2.1.2. ([\#11969](#11969))
- Prepare for rename of default Complement branch. ([\#11971](#11971))
- Fetch Synapse's version using a helper from `matrix-common`. ([\#11979](#11979))

Author: Sean Quah