BUG: Series __setitem__ gives wrong result with bool indexer
Series.__setitem__ gives wrong result with bool indexer and when length of new data matches the number of Trues and new data is neither a Series nor a numpy array

- [x] closes #30567
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry
