Move matrix-bridge-heisenbridge to its own container network

roles/custom/matrix-bridge-heisenbridge/tasks/validate_config.yml

@@ -0,0 +1,10 @@
+---
+
+- name: Fail if required heisenbridge settings not defined
+  ansible.builtin.fail:
+    msg: >-
+      You need to define a required configuration setting (`{{ item.name }}`).
+  when: "item.when | bool and vars[item.name] == ''"
+  with_items:
+    - {'name': 'matrix_heisenbridge_container_network', when: true}
+    - {'name': 'matrix_heisenbridge_homeserver_url', when: true}