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.

Fix missing "reverse_proxy" argument line 35

Related to:

- d96ce10d57
- https://github.com/mother-of-all-self-hosting/ansible-role-traefik/pull/6
- https://github.com/mother-of-all-self-hosting/ansible-role-traefik/issues/5

Various old guides mention this, but it seems like neither Element Web,
nor Element Desktop make use of it.

Element Web & Element Desktop use their own `config.json` configuration to figure out where
Element Call is.

Some Element Call setup resources say that `/.well-known/element/element.json` should be served on the base domain
and should contain content like this:

```json
{
	"call": {
		"widget_url": "https://call.element.example.com"
	}
}
```

We were already generating the file via `matrix-static-files`, but weren't serving it yet.

This patch makes sure it's served on the `matrix.` domain, which allows
people to set up serving on the base domain via a redirect or reverse-proxying.

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3562

`group_vars/matrix_servers` was correctly populating `matrix_static_files_file_matrix_client_property_org_matrix_msc4143_rtc_foci_auto` with a list, but:

- the defaults for these variables were hinting that hashmaps are necessary

- merging of `_auto` and `_custom` was done as if for hashmaps, not lists

As a result, `/.well-known/matrix/client` looked like this:

```json
{
	"org.matrix.msc4143.rtc_foci": {
		"livekit_service_url": "https://matrix.example.com/livekit-jwt-service",
		"type": "livekit"
	}
}
```

.. instead of what's expected as per MSC4143 (https://github.com/matrix-org/matrix-spec-proposals/pull/4143):

```json
{
	"org.matrix.msc4143.rtc_foci": [
		{
			"livekit_service_url": "https://matrix.example.com/livekit-jwt-service",
			"type": "livekit"
		}
	]
}
```

Regardless of our incorrectly formatted `org.matrix.msc4143.rtc_foci`
configuration in `/.well-known/matrix/client`, Element Web still seemed
to be able to discover LiveKit JWT Service (and by extension, LiveKit Server) correctly,
even without this fix.