fix(ci): add --omit-dir-times to UI rsync deploy

The gitea_ci user cannot set timestamps on /var/www/rpm/ which is
owned by root. Directory timestamps are irrelevant for static files.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/deploy-ui.yml

@@ -52,6 +52,7 @@ jobs:
             --archive \
             --verbose \
             --delete \
+            --omit-dir-times \
             --chmod D755,F644 \
             --include="index.html" \
             --include="assets/***" \