Remove matrix-nginx-proxy integration for matrix-bridge-mautrix-wsproxy

This probably never even worked anyway and was a leftover copy/paste
from some other role.

The docs (`docs/configuring-playbook-bridge-mautrix-wsproxy.md`) only
talk about `matrix_mautrix_wsproxy_hostname`, which was only used via
Traefik labels. The endpoint exposed via `matrix-nginx-proxy` (`/_matrix/wsproxy`)
hasn't been mentioned anywhere.

roles/custom/matrix-bridge-mautrix-wsproxy/tasks/main.yml

@@ -1,14 +1,5 @@
 ---
 
-- tags:
-    - setup-all
-    - setup-nginx-proxy
-    - install-all
-    - install-nginx-proxy
-  block:
-    - when: matrix_mautrix_wsproxy_enabled | bool
-      ansible.builtin.include_tasks: "{{ role_path }}/tasks/inject_into_nginx_proxy.yml"
-
 - tags:
     - setup-all
     - setup-mautrix-wsproxy