 Handling conversion of empty categorical with dtype_backend='pyarrow'
- [x] closes #59934
- [x] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests)
- [x] Added an entry in the latest `doc/source/whatsnew/v3.0.0.rst` file if fixing a bug or adding a new feature.

Following up on comments in #59935
Closing. Ref: https://github.com/pandas-dev/pandas/pull/59935#issuecomment-2392181218