Make shuffle pyx functions noexcept

[martindurant]

Fixes #476

@jakirkham , like this? The functions don't actually return anything.

Do we have any process to determine which codecs release the GIL? Given the performance discussions, this could be imporant.

[codecov]

Codecov Report

Merging #477 (975d45b) into main (1bc1e44) will increase coverage by 0.04%.
The diff coverage is n/a.

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #477      +/-   ##
===========================================
+ Coverage   99.95%   100.00%   +0.04%     
===========================================
  Files          56        56              
  Lines        2241      2242       +1     
===========================================
+ Hits         2240      2242       +2     
+ Misses          1         0       -1     

see 2 files with indirect coverage changes

[jakirkham]

Thanks Martin! 🙏

IIUC adding noexcept should be sufficient here (looking at this Cython doc section)

[jakirkham]

Thanks Martin! 🙏