MAINT: Clarify supported Stata dta versions
Test against old Stata versions and remove text indicating support
for versions which do not work reliably

closes #26667

- [x] closes #26667
- [X] tests added / passed
- [X] passes `black pandas`
- [X] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Not sure if a what's new is needed here. lgtm. yeah I would add a whatsnew indicating which versions are being removed for unreliability :-> ping on green. are these versions listed in the doc-string? @jreback I have gone through and removed any references to the unsupported versions.  There were none in docstrings; they were only in a few places that compared the version read to a minimum version.  thanks @bashtage 