For each of the 34 roles (3 clients, 9 bots, 22 bridges), this commit:
- Adds `_restart_necessary: false` default variable
- Adds `register:` directives to config/image/systemd tasks
- Computes `_restart_necessary` via set_fact (OR of all .changed results)
- Wires `(_restart_necessary | bool)` in group_vars/matrix_servers

This allows the systemd service manager to skip unnecessary restarts
when running install-* tags and nothing actually changed.

Service roles and complex multi-service roles will follow separately.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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

This commit adds copyright attirbutions in SPDX format to files for matrix-bot-go-neb, following the REUSE's specification.

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

* 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`

---------

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

commit cf8637efac
Author: Slavi Pantaleev <slavi@devture.com>
Date:   Sun Mar 24 19:14:57 2024 +0200

    Make devture_systemd_docker_base_ipv6_enabled automatically reconfigure geerlingguy/ansible-role-docker

    Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3218

commit dc7af3bc7d
Author: Slavi Pantaleev <slavi@devture.com>
Date:   Sun Mar 24 19:10:31 2024 +0200

    Replace matrix_ipv6_enabled with devture_systemd_docker_base_ipv6_enabled

    Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3218

commit 07e900d6a2
Author: Slavi Pantaleev <slavi@devture.com>
Date:   Sun Mar 24 19:01:51 2024 +0200

    Improve matrix_ipv6_enabled comments

commit 3f03ca7f69
Author: Tilo Spannagel <development@tilosp.de>
Date:   Sat Mar 9 19:27:50 2024 +0000

    Add setting to enable ipv6

Completely untested.

We expect `--tags=start` to handle systemd reloading, so we don't need
to do it manually each time we install/uninstall a .service file.

- forego removing Docker images - it's not effective anyway, because it
  only removes the last version.. which is a drop in the bucket, usually

- do not reload systemd - it's none of our business. `--tags=start`,
  etc., handle this

- combine all uninstall tasks under a single block, which only runs if
  we detect traces (a leftover systemd .service file) of the component.
  If no such .service is detected, we skip them all. This may lead to
  incorect cleanup in rare cases, but is good enough for the most part.

This paves the way for installing other roles into `roles/galaxy` using `ansible-galaxy`,
similar to how it's done in:

- https://github.com/spantaleev/gitea-docker-ansible-deploy
- https://github.com/spantaleev/nextcloud-docker-ansible-deploy

In the near future, we'll be removing a lot of the shared role code from here
and using upstream roles for it. Some of the core `matrix-*` roles have
already been extracted out into other reusable roles:

- https://github.com/devture/com.devture.ansible.role.postgres
- https://github.com/devture/com.devture.ansible.role.systemd_docker_base
- https://github.com/devture/com.devture.ansible.role.timesync
- https://github.com/devture/com.devture.ansible.role.vars_preserver
- https://github.com/devture/com.devture.ansible.role.playbook_runtime_messages
- https://github.com/devture/com.devture.ansible.role.playbook_help

We just need to migrate to those.