* Add a global config option for Docker network MTU

* Upgrade systemd_docker_base (v1.2.0-0 -> v1.3.0-0)

The new version includes `devture_systemd_docker_base_container_networks_driver_options`
due to 3cc7d12396

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3502

* Switch from passing matrix_playbook_docker_network_mtu to respecting devture_systemd_docker_base_container_networks_driver_options

Related to:
- 3cc7d12396
- https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3502

* Update all roles to versions that respect `devture_systemd_docker_base_container_networks_driver_options`

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Co-authored-by: Slavi Pantaleev <slavi@devture.com>

Supersedes https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3539

Related to https://github.com/metio/matrix-alertmanager-receiver/pull/42

My alerts seem to contain `annotations.alertname` in the payload, so the
default configuration (coming from the matrix-alertmanager-receiver README)
seems to be outdated or something.