Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3556

Update ghcr.io/element-hq/synapse Docker tag to v1.116.0

Update vectorim/element-web Docker tag to v1.11.79

Fix validate_config.yml

`devture_postgres_*` -> `postgres_*`

Upgrade Jitsi (v9646-1 -> v9753-0)

synapse-admin v0.10.3-etke17: add `Contact support` menu item

enable hookshot outbound webhooks

* WIP: add system-managed users to synapse-admin

* add missing users

* synapse-admin v0.10.3-etke15: Upgrade to react-admin v5

* v0.10.3-etke16

* fix linter

* add _auto and _custom vars

* Use 2 spaces before #noqa var-naming

---------

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

Update vectorim/element-web Docker tag to v1.11.78

`gpt-4o` will point to `gpt-4o-2024-08-06` after 2nd of October 2024
anyway. At that time, we can revert to pointing to `gpt-4o`.

The reason `gpt-4o-2024-08-06` was chosen now instead of `gpt-4o`:

- the `max_response_tokens` configuration was set to 16k, which matches
  `gpt-4o-2024-08-06`, but is too large for `gpt-4o` (max 4k)

- baibot's own configs for dynamically created agents, as well as static
  config examples use `gpt-4o-2024-08-06` and the larger
  `max_response_tokens` value

The playbook did not use to define a prompt for statically-defined
agents.

Since prompt variables support landed in v1.1.0
(see 2a5a2d6a4d)
it makes sense to make use of it for a better out-of-the-box experience
(see https://github.com/etkecc/baibot/issues/10).

Update dependency etherpad to v2.2.5-0

* 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>

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

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

synapse-admin v0.10.3-etke14: bulk registration works again, add ability to change avatars

Update joseluisq/static-web-server Docker tag to v2.33.0

1.3.0 fails to work against the new Synapse (v1.115.0) image.
See: https://github.com/matrix-org/synapse-s3-storage-provider/pull/114

Related to: https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3535

Update ghcr.io/element-hq/synapse Docker tag to v1.115.0

Seems like `default` is not a supported value and will not
make the bridge autoconfigure itself with the correct prefix anymore.

A value of `default` would be taken literally.

f9705b3323 reworked the configuration and missed wiring
these to the existing variables.

Update maintenance-upgrading-services.md

We'be already been going against upstream defaults and have been
enabling backfilling for a few other bridges (Messenger, Instagram, Telegram, Twitter).

Now I'm enabling backfilling by default for the remaining ones, for
consistency.

Related to:
- https://github.com/mautrix/gmessages/releases/tag/v0.5.0
- https://mau.fi/blog/2024-09-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.

Related to:
- https://github.com/mautrix/meta/releases/tag/v0.4.0
- https://mau.fi/blog/2024-09-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.