twine check warns on Linux & fails on Windows

[leofang]

Windows:

ERROR    `long_description` has syntax errors in markup and would not be       
         rendered on PyPI.                                                     
         No content rendered from RST source.                                  
WARNING  `long_description_content_type` missing. defaulting to `text/x-rst`.

https://github.com/NVIDIA/cuda-python/actions/runs/12310540533/job/34359283856?pr=296#step:4:2908

Linux:

/home/runner/_work/cuda-python/cuda-python/cuda_bindings/dist/cuda_python-12.6.2
.post1+222.g1def17e-cp313-cp313-manylinux_2_17_x86_64.manylinux2014_x86_64.whl: PASSED with warnings
WARNING  `long_description_content_type` missing. defaulting to `text/x-rst`.   
WARNING  `long_description` missing.   

https://github.com/NVIDIA/cuda-python/actions/runs/12310540533/job/34359283154?pr=296#step:5:2190

[vzhurba01]

https://github.com/NVIDIA/cuda-python/pull/296/files#diff-ec444582781b87b7476f7da1be059db3757d1b8a5c33cbe8fd1e72490844cd2f

Reminder to uncomment the TODO in this commit for action.yml as part of resolution.