BUG: The setting xrot=0 in DataFrame.hist() doesn't work with by and subplots #30288
- [x] closes #30288
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

@jreback, I have updated the whatsnew entry.  great thanks @souvik3333 