Fix missing kernels in CircleCI deployments

Co-Authored-By: Loïc Estève <[email protected]>

Author: agriyakhetarpal

jupyterlite_sphinx/jupyterlite_sphinx.py

@@ -512,7 +512,7 @@ def run(self):
 
         iframe_parent_div_id = uuid4()
         iframe_div_id = uuid4()
-        iframe_src = f'{prefix}/{app_path}{f"?{options}" if options else ""}'
+        iframe_src = f'{prefix}/{app_path}{f"index.html?{options}" if options else ""}'
 
         # Parent container (initially hidden)
         iframe_parent_container_div_start = (