Rename variable (matrix_user_username -> matrix_user_name)

roles/custom/matrix-base/tasks/setup_matrix_user.yml

@@ -15,7 +15,7 @@
 
 - name: Ensure Matrix user is created
   ansible.builtin.user:
-    name: "{{ matrix_user_username }}"
+    name: "{{ matrix_user_name }}"
     uid: "{{ omit if matrix_user_uid is none else matrix_user_uid }}"
     state: present
     group: "{{ matrix_user_groupname }}"