Related to:

- https://github.com/matrix-org/synapse/pull/15281
- https://github.com/matrix-org/synapse/pull/15282

Related to:

- e55269e14f
- 3d70cc393f
- 4fc85e5a92

Related to:

- https://github.com/matrix-org/rageshake/issues/69
- https://github.com/matrix-org/rageshake/pull/70

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2592

Warning! Potentially breaking change: https://github.com/matrix-org/matrix-hookshot/releases/tag/3.0.0

It wasn't used at all. It doesn't seem like there's a way to control
the log level, judging by:
- 8f9eea4114/.env.example
- 8f9eea4114/src/env.ts

Related to:

- 682d31c702
- ecbe0ddbe7
- f4fc83ac75

.. and https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2569

Related to:
- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2565
- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2566

This provides an additional security benefit. The password won't leak in
the process list anymore.

It will, additionally, be connected to the devture-postgres network, if
devture-postgres is enabled.

OpenAI changed the model a month ago and broke the bot.
This bump fixes it and adds the default model.

This allows people to try out the new Element X clients, which need to
run against the sliding-sync proxy (https://github.com/matrix-org/sliding-sync).

Supersedes https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2515

The code is based on the existing PR (#2515), but heavily reworked. Major changes:

- lots of internal refactoring and variable renaming

- fixed self-building to support non-amd64 architectures

- changed to talk to the homeserver locally, over the container network (not
  publicly)

- no more matrix-nginx-proxy support due to complexity (see below)

- no more `matrix_server_fqn_sliding_sync_proxy` in favor of
  `matrix_sliding_sync_hostname` and `matrix_sliding_sync_path_prefix`

- runs on `matrix.DOMAIN/sliding-sync` by default, so it can tried
  easily without having to create new DNS records

The variable was necessary when multiple playbooks could have
potentially tried to manage a shared `devture-traefik.serivce` systemd service
and shared `/devture-traefik` directory.

Since adcc6d9723086f65f1a72, we use our own `/matrix/traefik`
(`matrix-traefik.service`) installation and no conflicts can arise.
It's safe to always enable the role, just like we do with all the other roles.