TST: GH39126 Test barh plot with string and integer at the same column
- [x] closes #39126
- [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).

Great! Thanks @arch1baald 