Related to:
- https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3479
- https://github.com/mautrix/signal/releases/tag/v0.7.0
- https://mau.fi/blog/2024-08-mautrix-release/

It seems like the new version does not support a `/metrics` endpoint.
We skip keep the Ansible variables, but they're not doing anything.

Closes https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3481