Fix single typo Rraefik --> Traefik

Not sure why we were doing this.

LiveKit Server may utilize Valkey, but we don't configure it this way,
so there's no need to do it.

Necro-posting and notifying all subscribers for the purpose of preventing necro-posting is somewhat ironic

The action will be used to lock issues and PRs to prevent necro-posting on closed ones which have not had any activity in the past year.

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/4233

This doesn't make Prometheus automatically scrape metrics from LiveKit Server,
nor does it add a Grafana dashboard automatically, etc.

Still, it paves the way for that work being done.

Now that https://github.com/element-hq/element-web/pull/29471
is part of v1.11.96, we don't need to carry around this custom workaround.

This also reverts e5574a405e because:
- it was causing issues on some servers (not clear why)
- such workarounds are no longer necessary when doing multi-stage building.

"briges" -> "bridges"

This is a security patch for Synapse that fixes an actively exploited bug.