CI reporting improvements (#38230)

update

Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>

utils/check_bad_commit.py

@@ -144,7 +144,8 @@ def get_commit_info(commit):
         url = f"https://api.github.com/repos/huggingface/transformers/pulls/{pr_number}"
         pr_for_commit = requests.get(url).json()
         author = pr_for_commit["user"]["login"]
-        merged_author = pr_for_commit["merged_by"]["login"]
+        if pr_for_commit["merged_by"] is not None:
+            merged_author = pr_for_commit["merged_by"]["login"]
 
     if author is None:
         url = f"https://api.github.com/repos/huggingface/transformers/commits/{commit}"