BUG: `MultiIndex` displays incorrectly with a long element
- [x] Closes #52960
- [x] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests)
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit)
- [x] Added an entry in the latest `doc/source/whatsnew/v2.1.0.rst` file

https://github.com/pandas-dev/pandas/blob/721bd7a22efbd1c57f86fd61d6f0e668b79942ae/pandas/io/formats/printing.py#L417-L420
The `if` branch as shown above may never be visited, so `head` and `tail` may not be correctly set. This pull request fixes this problem.
Sure, thanks for your review! I'll make the changes ASAP. @mroeschke Hi, I've made the unit test. However, I'm not sure if this is the correct way to do, so would you mind giving some instructions if I'm not doing correctly? Thank you very much. Thanks @Charlie-XIAO 