Add support for synapse-http-antispam and integrate it with Draupnir

Supersedes https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/4284

roles/custom/matrix-synapse/tasks/ext/synapse-http-antispam/setup_uninstall.yml

@@ -0,0 +1,11 @@
+# SPDX-FileCopyrightText: 2025 MDAD project contributors
+# SPDX-FileCopyrightText: 2025 Catalan Lover <catalanlover@protonmail.com>
+#
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+---
+
+- name: Ensure synapse-http-antispam doesn't exist
+  ansible.builtin.file:
+    path: "{{ matrix_synapse_ext_path }}/synapse-http-antispam"
+    state: absent