fix(web-app-discourse): remove run_after dep on web-app-wordpress

Discourse must come up before Wordpress, not after: the wp-discourse
plugin install in roles/web-app-wordpress/tasks/plugins/wp-discourse.yml
runs `container exec discourse rake api_key:create_master[...]` and
related rails commands during the Wordpress play, so the Discourse
container has to exist by then. The previous declaration
`discourse.run_after: [web-app-wordpress]` produced the opposite order
and crashed the GHA universal-deploy with
"Error response from daemon: No such container: discourse" before the
Discourse role itself ever ran (job 73306260674).

The matching wordpress-side run_after addition (which now lists
web-app-discourse as a Wordpress prerequisite) lands in a separate
commit so the two halves of the order flip stay independently
revertable.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

roles/web-app-discourse/meta/services.yml

@@ -42,8 +42,6 @@ discourse:
   ports:
     local:
       http: 8020
-  run_after:
-  - web-app-wordpress
   lifecycle: beta
 css:
   enabled: true