N.B. requires requirements.txt to be generated in repo root beforehand

#15514 introduced a regression where Synapse would encounter
`PartialDownloadError`s when fetching OpenID metadata for certain
providers on startup. Due to #8088, this prevents Synapse from starting
entirely.

Revert the change while we decide what to do about the regression.

Pushers tend to make many connections to the same HTTP host
(e.g. a new event comes in, causes events to be pushed, and then
the homeserver connects to the same host many times). Due to this
the per-host HTTP connection pool size was increased, but this does
not make sense for other SimpleHttpClients.

Add a parameter for the connection pool and override it for pushers
(making a separate SimpleHttpClient for pushers with the increased
configuration).

This returns the HTTP connection pool settings to the default Twisted
ones for non-pusher HTTP clients.

Adds an optional keyword argument to the /relations API which
will recurse a limited number of event relationships.

This will cause the API to return not just the events related to the
parent event, but also events related to those related to the parent
event, etc.

This is disabled by default behind an experimental configuration
flag and is currently implemented using prefixed parameters.

* Bump types-pillow from 9.4.0.19 to 9.5.0.2

Bumps [types-pillow](https://github.com/python/typeshed) from 9.4.0.19 to 9.5.0.2.
- [Release notes](https://github.com/python/typeshed/releases)
- [Commits](https://github.com/python/typeshed/commits)

MSC3983 provides a way to request multiple OTKs at once from appservices,
this extends this concept to the Client-Server API.

Note that this will likely be spit out into a separate MSC, but is currently part of
MSC3983.

Cleans-up the schema delta files:

* Removes no-op functions.
* Adds missing type hints to function parameters.
* Fixes any issues with type hints.

This also renames one (very old) schema delta to avoid a conflict
that mypy complains about.

* no push for excluded room from sync

* add changelog
Signed-off-by: Maghen Calinghee <maghen.calinghee@beta.gouv.fr>

* correct changelog

* Docs: Add Nginx loadbalancing example with sticky mxid for workers

Add example nginx configuration snippet that

* does load balancing for workers
* respects mxid part of the token
  * from both url parameter and auth header
  * and handles since parameter

Thanks to @olmari for pushing me to write this and testing the configs

Signed-off-by: Tatu Wikman <tatu.wikman@gmail.com>

* Add changelog entry

Signed-off-by: Tatu Wikman <tatu.wikman@gmail.com>

* Update codeblock formatter

Co-authored-by: Dirk Klimpel <5740567+dklimpel@users.noreply.github.com>

* Remove indirectly related nginx-config

Signed-off-by: Sami Olmari <sami@olmari.fi>

* Proper definition of action how to target username for worker

Signed-off-by: Sami Olmari <sami@olmari.fi>

* Change "nginx" to general "reverse proxy" as it's concept now.

Signed-off-by: Sami Olmari <sami@olmari.fi>

* Wording in better English

Co-authored-by: Tatu Wikman <tatu.wikman@gmail.com>

* rename changelog entry to have correct extension

---------

Signed-off-by: Tatu Wikman <tatu.wikman@gmail.com>
Signed-off-by: Sami Olmari <sami@olmari.fi>
Co-authored-by: Dirk Klimpel <5740567+dklimpel@users.noreply.github.com>
Co-authored-by: Sami Olmari <sami@olmari.fi>
Co-authored-by: Sami Olmari <sami+github@olmari.fi>

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

Update the `check_schema_delta` script to account for when the schema version has been bumped locally (#15466)

It can be useful to always return the fallback key when attempting to
claim keys. This adds an unstable endpoint for `/keys/claim` which
always returns fallback keys in addition to one-time-keys.

The fallback key(s) are not marked as "used" unless there are no
corresponding OTKs.

This is currently defined in MSC3983 (although likely to be split out
to a separate MSC). The endpoint shape may change or be requested
differently (i.e. a keyword parameter on the current endpoint), but the
core logic should be reasonable.

* Bump types-jsonschema from 4.17.0.6 to 4.17.0.7

Bumps [types-jsonschema](https://github.com/python/typeshed) from 4.17.0.6 to 4.17.0.7.
- [Release notes](https://github.com/python/typeshed/releases)
- [Commits](https://github.com/python/typeshed/commits

)

---
updated-dependencies:
- dependency-name: types-jsonschema
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

* Changelog

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: GitHub Actions <github-actions[bot]@users.noreply.github.com>

* Bump types-netaddr from 0.8.0.7 to 0.8.0.8

Bumps [types-netaddr](https://github.com/python/typeshed) from 0.8.0.7 to 0.8.0.8.
- [Release notes](https://github.com/python/typeshed/releases)
- [Commits](https://github.com/python/typeshed/commits

)

---
updated-dependencies:
- dependency-name: types-netaddr
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

* Changelog

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: GitHub Actions <github-actions[bot]@users.noreply.github.com>