Update prometheus (2.29.1 -> 2.29.2)

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/1247

Fix incorrect docker version tag for matrix-appservice-irc

Related to https://github.com/devture/exim-relay/pull/11

This bridge doesn't support SQLite anyway, so it's not necessary
to carry around configuration fields and code for migration from SQLite
to Postgres. There's nothing to migrate.

This configuration is supposed to be kept clean and not reference variables defined in other roles.

`group_vars/matrix_servers` redefines these to hook our various roles together.

https://github.com/matrix-org/matrix-appservice-irc/releases/tag/0.30.0

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1236

Element web/desktop has just been updated to fix some regressions in regard to VoIP.

The Github link is just a redirect to Tulir's own GitLab, so I replaced the self-build link
The docker container repository was rearranged hierarchically (dock.mau.dev/tulir/mautrix-facebook -> dock.mau.dev/mautrix/facebook)
Tagged versions have been made available, thus :latest -> :v0.3.1