`matrix_container_images_self_build` was not really doing anything
anymore. It previously was influencing `matrix_*_self_build` variables,
but it's no longer the case since some time ago.

Individual `matrix_*_self_build` variables are still available.
People that would like to toggle self-building for a specific component
ought to use those.

These variables are also controlled automatically (via
`group_vars/matrix_servers`) depending on `matrix_architecture`.

In other words, self-building is being done automatically for
all components when they don't have a prebuilt image for the specified
architecture. Some components only support `amd64`, while others also
have images for other architectures.

ma1sd 2.4.0 announced experimental support for arm64.
We're making use of those arm64 images instead of self-building.

Update Jitsi to stable-4627-1

Ma1sd v2.4.0

Documentation of the variables added in the PR #548

Actualizo con los cambios en el repositorio base de Slavi.

Improve the example Traefik config.

Add variables to fine tune jitsi

Use playbook variables instead of textual place-holders for the domain names.

Related to #549 (Github Pull Request)

Added config hint for SMS verification

Related to https://github.com/vector-im/riot-web/pull/13914

Fixes #502 (Github Issue)

Fixes #545 (Github Issue).

Certain people organize their inventory in a different way
and we'd like to accommodate them.

Related to #542 (Github Issue).

Fixes #542 (Github Issues).

Update matrix-sms-bridge

Fixes #539 (Github Issue).

Fix missing conf for double puppeting in mx-puppet-slack

Fixes #523 (Github Issue).

Besides /_synapse/admin, there are other things like
/_synapse/oidc, etc.

We should just proxy everything.

Fixes #534 (Github Issue).

Related to #529 (Github Issue).

There's no change in the source code. Just a release bump for packaing
reasons. It doesn't matter much for us here, but let's be on the latest
tag anyway.

typo