Use config.yml on the server for baibot

Closes https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/4039

Partially reverts 30dad8ba27 which renamed
`config.yml` to `config.yaml` in the playbook and on the server, for
consistency with the rest of the playbook.

The problem is that:

- baibot defaults to looking for `config.yml`, not `config.yaml` (as provided).
  This can be worked around by specifying a new `BAIBOT_CONFIG_FILE_PATH=config.yaml`
  environment variable. This brings more complexity.

- renaming the target file (on the server) to `config.yaml` means people
  with an existing installation would drag around the old file (`config.yml`) as well,
  unless we create a new Ansible task (`ansible.builtin.file` with `state: absent`) to remove
  the old file. This brings more complexity as well.

https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/4039 adjusts where the file is mounted,
which fixes the immediate problem (baibot not starting), but still means
people will end up with 2 config files for baibot (`config.yml` and `config.yaml`).

This patch, reverts a bit more, so that we still continue to use `config.yml` on the server.
People who have upgraded within the last ~17 hours may end up with 2 files, but it shouldn't be too many of them.

roles/custom/matrix-bot-baibot/tasks/install.yml

@@ -17,7 +17,7 @@
 - name: Ensure baibot configuration installed
   ansible.builtin.copy:
     content: "{{ matrix_bot_baibot_configuration | to_nice_yaml(indent=2, width=999999) }}"
-    dest: "{{ matrix_bot_baibot_config_path }}/config.yaml"
+    dest: "{{ matrix_bot_baibot_config_path }}/config.yml"
     mode: 0644
     owner: "{{ matrix_user_username }}"
     group: "{{ matrix_user_groupname }}"

roles/custom/matrix-bot-baibot/templates/systemd/matrix-bot-baibot.service.j2

@@ -29,7 +29,7 @@ ExecStartPre={{ devture_systemd_docker_base_host_command_docker }} create \
 			--read-only \
 			--network={{ matrix_bot_baibot_container_network }} \
 			--env-file={{ matrix_bot_baibot_config_path }}/env \
-			--mount type=bind,src={{ matrix_bot_baibot_config_path }}/config.yaml,dst=/app/config.yaml,ro \
+			--mount type=bind,src={{ matrix_bot_baibot_config_path }}/config.yml,dst=/app/config.yml,ro \
 			--mount type=bind,src={{ matrix_bot_baibot_data_path }},dst=/data \
 			--tmpfs=/tmp:rw,noexec,nosuid,size=1024m \
 			{% for arg in matrix_bot_baibot_container_extra_arguments %}