Update ai branch to ai-services-ga

Author: dgnicholson

antora-playbook.yml

@@ -57,7 +57,7 @@ content:
   - url: https://github.com/couchbaselabs/docs-columnar
     branches: [main]
   - url: https://github.com/couchbaselabs/docs-ai
-    branches: [main]
+    branches: [ai-services-ga]
 asciidoc:
   attributes:
     site-navigation-data-path: _/js/site-navigation-data.js