WEB: Better management of releases
Added releases sorting by version number and sorting out obsolete releases in web/pandas_web.py

- [ ] closes #50885 
- [x] Tests added and passed
- [x] All code checks passed

Hi @datapythonista !
Added this PR and tests, but was not sure what you've meant in original issue by:
> Maybe just a tests/test_pandas_web.py in the same directory as the script, and calling pytest on that directory in the documentation build is the best option.

Could not figure out how new tests should be called.
Also added `mock_response` fixture that can be used for testing other web features.  > Could not figure out how new tests should be called. Also added `mock_response` fixture that can be used for testing other web features.

Good point. I think the normal tests just call pytest for the pandas/ directory. In the CI job to build the website and docs we could add a step to call pytest for the tests in web/. I think that's what makes sense, but other ideas are welcome. > > Could not figure out how new tests should be called. Also added `mock_response` fixture that can be used for testing other web features.
> 
> Good point. I think the normal tests just call pytest for the pandas/ directory. In the CI job to build the website and docs we could add a step to call pytest for the tests in web/. I think that's what makes sense, but other ideas are welcome.

Can you please point me out a file with CI job for docs and website? Sorry, I'm new to the project. > Can you please point me out a file with CI job for docs and website? Sorry, I'm new to the project.

https://github.com/pandas-dev/pandas/blob/main/.github/workflows/docbuild-and-upload.yml > > Can you please point me out a file with CI job for docs and website? Sorry, I'm new to the project.
> 
> https://github.com/pandas-dev/pandas/blob/main/.github/workflows/docbuild-and-upload.yml

Thanks a lot! Added "Test website" step to ci job. Amazing job, thanks for taking care of this @Dukastlik, and sorry that reviews took a while. 