Fix workflow runner label to match act_runner defaults

Runner registered with default labels (ubuntu-latest) instead of
self-hosted — update runs-on to match.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/deploy.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   deploy:
-    runs-on: self-hosted
+    runs-on: ubuntu-latest
 
     steps:
       - name: Checkout