Hopefully fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2849

Related to:
- https://github.com/matrix-org/synapse/issues/16101
- https://github.com/matrix-org/synapse/issues/16208

matrix-synapse/tasks/setup_uninstall.yml would previously not run unless
Synapse was completely disabled.

`spam_checker` has been deprecated for quite a while.
While it still probably works and while newer versions of
mjolnir-antispam still use it, we should switch to the new API.

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

Related to:
- e4f545c452
- 2481b7dfa4

We've prepared for this by adding the `main` process to the `instance_map` a long time ago,
in 49cb8b7b11.

Related to 0f02f0b4da

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

Now that Element v1.11.32 is out and https://github.com/vector-im/element-web/issues/19605 is fixed
(by https://github.com/matrix-org/matrix-react-sdk/pull/10975), we don't
need to force-disable this login type.

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

Related to:

- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2698
- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2700

This was mostly affecting the stream writer (events) worker, which was
being reported as unhealthy. It wasn't causing any issues, but it just
looked odd and was confusing people.

As an alternative to hitting the regular `/health` healthcheck route (on
the "client" API which this stream writer does not expose),
we may have went for hitting some "replication" API endpoint instead.

This is more complicated and likely unnecessary.

This is meant to keep the configuration tidy for non-worker setups.

Related to 49cb8b7b11

Related to https://github.com/matrix-org/synapse/pull/15491

This doesn't hurt to be done early on, while still on Synapse v1.83.0.

We'll be able to remove the `worker_replication_*` settings later,
when Synapse v1.84.0 gets released and starts making use of the new
`main` instance in the instance map instead of looking at the
`worker_replication_*` settings.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2669

Removed in 04b9483f0d (2022-11-28) when switching from matrix-postgres to
the devture-postgres external Ansible role.
More details: https://github.com/spantaleev/matrix-docker-ansible-deploy/blob/master/CHANGELOG.md#matrix-postgres-has-been-replaced-by-the-comdevtureansiblerolepostgres-external-role

The `import_synapse_sqlite_db.yml` file and documentation has been adapted somewhat compared to before, so that:

- it doesn't try to start Postgres automatically. You need to handle
  this part manually
- it doesn't rely on the integrated Postgres and may potentially work
  with external Postgres instances just the same
- it doesn't wipe out the whole database anymore. By default, we assume
  it's empty anyway and there's no need for such things. If it's not,
  then it's also probably dangerous to be so destructive.

This is all completely untested, but will hopefully work.

It's the same as `matrix_docker_network` for now, so this practically
doesn't change anything.

Fixup related to https://github.com/matrix-org/synapse/pull/15431

Related to:

- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2656
- e4a25d022c

Related to:

- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2656
- 4af0aec54d

* Update homeserver.yaml.j2

* Update configuring-playbook-ldap-auth.md

* Update homeserver.yaml.j2