GRM-161: Fix register.yml service start and bump devx to v0.50.5 (#238)

- Fix register.yml premature service start (removed systemctl start before unit file exists)
- Replace broken inline Python in ci.yml auto-merge with devx.ci.wait_for_checks
- Bump devx from v0.50.0 to v0.50.5

GRM-161

ansible/roles/gitea_runner/tasks/register.yml

@@ -44,16 +44,6 @@
     ('already exists' not in gitea_runner_register_output.stdout | default(''))
   timeout: 60
 
-- name: Ensure runner service is running after registration
-  ansible.builtin.command: systemctl --user start gitea-runner
-  become: true
-  become_user: "{{ gitea_runner_service_user }}"
-  environment:
-    XDG_RUNTIME_DIR: "/run/user/{{ gitea_runner_uid }}"
-    DBUS_SESSION_BUS_ADDRESS: "unix:path=/run/user/{{ gitea_runner_uid | default(0) }}/bus"
-  changed_when: true
-  when:
-    - gitea_runner_systemd_available.stat.exists
-    - gitea_runner_docker_rootless_setup
-    - gitea_runner_register_output is defined
-    - gitea_runner_register_output.rc | default(1) == 0
+# Note: service start is handled by service.yml (included after register.yml
+# in install_runner.yml). Starting here fails because the systemd unit file
+# has not been created yet.