BUG: float-like string, trailing 0 truncation
- [x] closes #38708
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

also pls rebase  Moved tests, added issue number, fixed conflict thanks @mzeitlin11  @meeseeksdev backport 1.2.x