We expect a string, which is parsed via `from_json`.

This matches previous usage in inventories, as well as what the
user-controlled precedessor of this variable (`matrix_synapse_admin_configuration_extension_json`)
is like.

Related to 997e6ca611

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/4459

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/4445

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/4445

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

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

This:

- brings consistency - no more mixing `_name_prefix` and `_registry_prefix`
- adds extensibility - a future patch will allow reconfiguring all registry prefixes for all roles in the playbook

We still have `_docker_` vs `_container_` inconsistencies.
These may be worked on later.

`-t` works on both old and new Docker versions, so it's best to use that.

* This push request is about handling Traefik ipallowlist to synapse-admin application.

It's my first push request. If I forgot something please let me know. :-)

* Changed position of variable and naming for better expandebility of traefik options

* Remove useless `noqa var-naming` comment and too many blank lines at the end of the file

---------

Co-authored-by: AkDk7 <joerg@pannbacker.email>
Co-authored-by: Slavi Pantaleev <slavi@devture.com>

https://github.com/etkecc/synapse-admin/releases/tag/v0.10.3-etke31

Related to:
- https://github.com/etkecc/synapse-admin/pull/126
- https://github.com/etkecc/synapse-admin/releases/tag/v0.10.3-etke27

People who wish to disable this and keep their `/.well-known/matrix/client` file tidier
can do it via:

```yml
matrix_static_files_file_matrix_client_property_cc_etke_synapse_admin_enabled: false
```