Restore invocation of matrix-mailer migration tasks

Seems like calling these tasks got removed at some point
while merge the `bye-bye-nginx-proxy` branch.

roles/custom/matrix_playbook_migration/tasks/main.yml

@@ -47,6 +47,12 @@
   block:
     - ansible.builtin.include_tasks: "{{ role_path }}/tasks/uninstall_matrix_ssl.yml"
 
+- tags:
+    - setup-all
+    - install-all
+  block:
+    - ansible.builtin.include_tasks: "{{ role_path }}/tasks/migrate_matrix_mailer.yml"
+
 - when: devture_traefik_enabled | bool
   tags:
     - setup-all