Remove unsupported use param from nginx service task

The `use` directive was consumed by the `service` action plugin to
force the generic SysV `service` backend instead of auto-detecting
systemd. Newer ansible-core (2.20+) no longer handles it in the action
plugin, so it gets passed through to the underlying module and fails:

    Unsupported parameters for (ansible.legacy.service) module: use

Dropping it lets the service module auto-detect the init system, which
is systemd on Trellis's supported Ubuntu targets.

Fixes #1668

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: swalkinshaw

roles/nginx/tasks/main.yml

@@ -60,4 +60,3 @@
     name: nginx
     enabled: yes
     state: started
-    use: service