fix: run cities labeler from its release image

Pull git.cosocial.info/cosocial-canada/atproto-cosocial-labeler instead of
cloning and building on the server, which took several minutes per deploy.
Watchtower picks up new :latest releases.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/workflows/deploy.yml

@@ -65,7 +65,6 @@ jobs:
           if [ -n "${{ vars.PDS_CITIES_HOSTNAME }}" ]; then
             cat >> vars/main.yml <<EOF
           pds_cities_enabled: true
-          pds_cities_repo: ${{ vars.PDS_CITIES_REPO }}
           pds_cities_hostname: ${{ vars.PDS_CITIES_HOSTNAME }}
           pds_cities_app_password: ${{ secrets.PDS_CITIES_APP_PASSWORD }}
           pds_cities_signing_key: ${{ secrets.PDS_CITIES_SIGNING_KEY }}