matrix-element-admin: switch to modern community.docker docker_image modules

Replaces `community.docker.docker_image` with the modern
`docker_image_pull` module. Drops the `ansible_version` compatibility
ladder and the now-redundant `_container_image_force_pull` variable
(the new pull module handles registry refresh natively via `pull: always`).

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/5191.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

roles/custom/matrix-element-admin/tasks/install.yml

@@ -32,11 +32,9 @@
   register: matrix_element_admin_support_files_result
 
 - name: Ensure Element Admin container image is pulled
-  community.docker.docker_image:
+  community.docker.docker_image_pull:
     name: "{{ matrix_element_admin_container_image }}"
-    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
-    force_source: "{{ matrix_element_admin_container_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_element_admin_container_image_force_pull }}"
+    pull: always
   when: "not matrix_element_admin_container_image_self_build | bool"
   register: matrix_element_admin_container_image_pull_result
   retries: "{{ devture_playbook_help_container_retries_count }}"

roles/custom/matrix-element-admin/tasks/validate_config.yml

@@ -24,3 +24,11 @@
       Element Admin with a path prefix other than '/' is not supported yet.
       You have configured matrix_element_admin_path_prefix to '{{ matrix_element_admin_path_prefix }}'.
   when: "matrix_element_admin_path_prefix != '/'"
+
+- name: (Deprecation) Catch and report renamed Element Admin variables
+  ansible.builtin.fail:
+    msg: >-
+      The variable `{{ item.old }}` is deprecated. Please use `{{ item.new }}` instead.
+  when: "lookup('ansible.builtin.varnames', ('^' + item.old + '$'), wantlist=True) | length > 0"
+  with_items:
+    - {'old': 'matrix_element_admin_container_image_force_pull', 'new': '<removed> (the new community.docker.docker_image_pull module handles this natively)'}