REGR: fillna on f32 column raising for f64
- [x] closes #43424
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [x] whatsnew entry

For now have put whatsnew in 1.3.3, but might be better for 1.4 since regression is later (worked in 1.1.5) and the `can_hold_element` change causes subtle indexing behavior differences (but that are now more consistent between int and float)