I'm getting this error when I try converting certain `Series` to datetime using `pd.to_datetime`, even though I pass `errors='ignore'` ```python _ = pd.to_datetime(pd.Series([['a']]*50), errors='ignore') # works _ = pd.to_datetime(pd.Series([['a']]*51), errors='ignore') # error ``` ```python Traceback (most recent call last): File "<stdin>", line 1, in <module> File "C:\Python38\lib\site-packages\pandas\core\tools\datetimes.py", line 801, in to_datetime cache_array = _maybe_cache(arg, format, cache, convert_listlike) File "C:\Python38\lib\site-packages\pandas\core\tools\datetimes.py", line 173, in _maybe_cache if not should_cache(arg): File "C:\Python38\lib\site-packages\pandas\core\tools\datetimes.py", line 137, in should_cache unique_elements = set(islice(arg, check_count)) TypeError: unhashable type: 'list' ```