Enable self-building for cactus-comments on non-amd64 architectures

The container image has only ever been available for amd64,
so not enabling self-building for the other architectures was a mistake
that orignally landed in:
https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2089

group_vars/matrix_servers

@@ -2156,7 +2156,7 @@ matrix_cactus_comments_enabled: false
 matrix_cactus_comments_as_token: "{{ '%s' | format(matrix_homeserver_generic_secret_key) | password_hash('sha512', 'cactus.as.token', rounds=655555) | to_uuid }}"
 matrix_cactus_comments_hs_token: "{{ '%s' | format(matrix_homeserver_generic_secret_key) | password_hash('sha512', 'cactus.hs.token', rounds=655555) | to_uuid }}"
 
-matrix_cactus_comments_container_image_self_build: "{{ matrix_architecture not in ['amd64', 'arm32', 'arm64'] }}"
+matrix_cactus_comments_container_image_self_build: "{{ matrix_architecture not in ['amd64'] }}"
 matrix_cactus_comments_systemd_required_services_list: |
   {{
     (['docker.service'])