ted-rdf-docs: remove main branch from staging env

Author: yfanti

antora-playbook.yml

@@ -76,7 +76,7 @@ content:
   ### TED Semantic Web Service
   - url: https://github.com/OP-TED/ted-rdf-docs
     start_path: docs/antora
-    branches: main, develop
+    branches: develop
 
   ### model2owl
   - url: https://github.com/OP-TED/ted-model2owl-docs