CI: Fix version openpyxl
- [ ] closes #29854 
- [ ] tests added / passed
- [ ] passes `black pandas`
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

https://bitbucket.org/openpyxl/openpyxl/issues/1373/broken-writer-with-lxml-defusedxml

Looks like there is a breaking change on openpyxl, so could limit it to `<=3.0.1` to avoid upgrading to the latest version until they fix the issue. Thanks for the fix @charlesdong1991 

I don't think we want this. This will fix the error in the documentation, but `.to_excel()` will keep broken. I think we want an actual fix. oh, sorry, did not notice your comment when i was committing @datapythonista 

thanks for your review, i thought this was only a doc error since I only observed this doc error in my another failed PR, I will take a another look, or you mean you want an actual fix from `openpyxl` side? > or you mean you want an actual fix from openpyxl side?

The behavior that is failing in the docbuild should be made into a test (which will currently fail with new openpyxl) which we then need to fix on our end. that said, we could add a test and xfail it to avoid blocking for now (while keeping a fixed version of openpyxl). > that said, we could add a test and xfail it to avoid blocking for now (while keeping a fixed version of openpyxl).

sounds good Thanks for both of your review @jreback and @jbrockmendel 

I made a new test and xfail if version of openpyxl if newer than 3.0.1, pls take a look to see if it is something we want now to avoid this blocker for other PRs. LGTM.  Merging so we can get the CI back up Is there an issue for the openpyxl regression? (here in pandas or upstream) > Is there an issue for the openpyxl regression? (here in pandas or upstream)

Potentially this: 
https://bitbucket.org/openpyxl/openpyxl/issues/1373/broken-writer-with-lxml-defusedxml