Revert "Removed need for license"

This reverts commit 5207f363f7e281577087d7202d066b5a0832eaea.

src/submission/submit.py

@@ -66,8 +66,7 @@ def add_new_eval(
     try:
         license = model_info.cardData["license"]
     except Exception:
-        license = '?'
-        # return styled_error("Please select a license for your model")
+        return styled_error("Please select a license for your model")
 
     modelcard_OK, error_msg = check_model_card(model)
     if not modelcard_OK: