Not tested but shouldn't break something

The OAuth credentials method seems to be the only viable way to
configure the mx-puppet-bridge now. Legacy tokens can no longer be
created, and the other methods (xoxs and xoxc tokens) come with warnings
about them being against Slack's terms of service.

(untested change, but unlikely to cause breakage)

Synapse v1.51.0 requires to be built with BuildKit since
https://github.com/matrix-org/synapse/pull/11691

The `docker_image` Ansible module does not support BuildKit
(https://github.com/ansible-collections/community.general/issues/514),
so we had to switch to a `docker build` call.

Fixes a issue with room version 1.

Merging has to wait until ARM images are built ofc.

v1.50.0 was found to be buggy for people using a `webclient` listener.
This is fixed in v1.50.1.

We don't use such a listener, so we weren't affected anyway.

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1544

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1498

Hopefully fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1518

Discussed here: https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1510

This is the equivalent of b1b4ba501f for the matrix-dendrite role.

This brings matrix-dendrite.service in line with all the other services.