Disable CI auto-build until an Actions runner is available.

Push and pull request triggers queue runs that sit forever with no runner. Keep the job and allow manual dispatch only so it can be turned back on later.

.gitea/workflows/ci.yml

@@ -1,9 +1,9 @@
 name: CI
 
+# Auto-build off until an Actions runner is available.
+# Restore push and pull_request triggers when a runner is registered.
 on:
-  push:
-    branches: [master, main]
-  pull_request:
+  workflow_dispatch:
 
 jobs:
   build: