MAINT: remove `_cosine.h` changes again.
MAINT: remove `_cosine.h` changes again.

Somehow this changes the numerical result, and it's not a SciPy bug
but a Python or glibc one. Not worth the time investigating more now,
so let's instead just silence the warning when wanting to add a CI
job with `-Werror`.

scipy/scipy,scipy/scipy,zerothi/scipy,andyfaff/scipy,anntzer/scipy,anntzer/scipy,vigna/scipy,zerothi/scipy,ilayn/scipy,mdhaber/scipy,anntzer/scipy,andyfaff/scipy,grlee77/scipy,perimosocordiae/scipy,mdhaber/scipy,endolith/scipy,zerothi/scipy,endolith/scipy,endolith/scipy,matthew-brett/scipy,rgommers/scipy,zerothi/scipy,ilayn/scipy,ilayn/scipy,andyfaff/scipy,WarrenWeckesser/scipy,scipy/scipy,scipy/scipy,vigna/scipy,WarrenWeckesser/scipy,mdhaber/scipy,WarrenWeckesser/scipy,mdhaber/scipy,grlee77/scipy,mdhaber/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,grlee77/scipy,rgommers/scipy,endolith/scipy,anntzer/scipy,Stefan-Endres/scipy,perimosocordiae/scipy,Stefan-Endres/scipy,ilayn/scipy,tylerjereddy/scipy,zerothi/scipy,scipy/scipy,perimosocordiae/scipy,matthew-brett/scipy,Stefan-Endres/scipy,andyfaff/scipy,grlee77/scipy,matthew-brett/scipy,ilayn/scipy,rgommers/scipy,endolith/scipy,anntzer/scipy,tylerjereddy/scipy,WarrenWeckesser/scipy,perimosocordiae/scipy,vigna/scipy,vigna/scipy,matthew-brett/scipy,endolith/scipy,WarrenWeckesser/scipy,perimosocordiae/scipy,Stefan-Endres/scipy,matthew-brett/scipy,zerothi/scipy,tylerjereddy/scipy,andyfaff/scipy,tylerjereddy/scipy,vigna/scipy,mdhaber/scipy,anntzer/scipy,grlee77/scipy,rgommers/scipy,Stefan-Endres/scipy,perimosocordiae/scipy,rgommers/scipy,tylerjereddy/scipy,andyfaff/scipy,scipy/scipy,ilayn/scipy