Do not run matrix-nginx-proxy config injection tasks unless necessary

These `init.yml` (now `inject_into_nginx_proxy.yml`) tasks do not need
to `always` run. They only need to run for `setup-all` and
`setup-nginx-proxy`. Unless we're dealing with these 2 tags, we can
spare ourselves a lot of work.

This patch also moves the `when` statement from `init.yml` into
`main.yml` in an effort to further optimize things by potentially
avoiding the extra file include.

roles/custom/matrix-synapse/tasks/inject_into_nginx_proxy.yml

@@ -2,17 +2,17 @@
 
 # Unless `matrix_synapse_workers_enabled_list` is explicitly defined,
 # we'll generate it dynamically.
-- ansible.builtin.include_tasks: "{{ role_path }}/tasks/synapse/workers/init.yml"
-  when: "matrix_synapse_enabled and matrix_synapse_workers_enabled and matrix_synapse_workers_enabled_list | length == 0"
+- ansible.builtin.include_tasks: "{{ role_path }}/tasks/synapse/workers/inject_into_nginx_proxy.yml"
+  when: "matrix_synapse_workers_enabled | bool and matrix_synapse_workers_enabled_list | length == 0"
 
 - name: Ensure workers are injected into various places
   ansible.builtin.include_tasks: "{{ role_path }}/tasks/synapse/workers/util/inject_worker.yml"
   with_items: "{{ matrix_synapse_workers_enabled_list }}"
   loop_control:
     loop_var: matrix_synapse_worker_details
-  when: matrix_synapse_enabled | bool and matrix_synapse_workers_enabled | bool
+  when: matrix_synapse_workers_enabled | bool
 
-- when: matrix_synapse_enabled | bool and matrix_synapse_metrics_proxying_enabled | bool
+- when: matrix_synapse_metrics_proxying_enabled | bool
   block:
     - name: Fail if matrix-nginx-proxy role already executed
       ansible.builtin.fail:

roles/custom/matrix-synapse/tasks/main.yml

@@ -1,8 +1,19 @@
 ---
 
-- ansible.builtin.import_tasks: "{{ role_path }}/tasks/init.yml"
+- when: matrix_synapse_enabled | bool
+  ansible.builtin.import_tasks: "{{ role_path }}/tasks/inject_into_nginx_proxy.yml"
   tags:
-    - always
+    - setup-all
+    - setup-synapse
+    - start
+    - start-all
+    - start-group
+    - restart
+    - restart-all
+    - restart-group
+    - stop
+    - stop-all
+    - stop-group
 
 - ansible.builtin.import_tasks: "{{ role_path }}/tasks/validate_config.yml"
   when: run_setup | bool and matrix_synapse_enabled | bool