fix: regress_out for more threads than 64

[Intron7]

Fix a potential bug for regress out where more than 64 threads leads to a hard crash

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 78.25%. Comparing base (d337b40) to head (86916b1).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/scanpy/preprocessing/_simple.py	66.66%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3954      +/-   ##
==========================================
- Coverage   78.26%   78.25%   -0.01%     
==========================================
  Files         117      117              
  Lines       12633    12638       +5     
==========================================
+ Hits         9887     9890       +3     
- Misses       2746     2748       +2     

Flag	Coverage Δ
hatch-test.low-vers	77.59% <66.66%> (-0.01%)	⬇️
hatch-test.pre	77.21% <66.66%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/scanpy/preprocessing/_simple.py	90.44% <66.66%> (-0.47%)	⬇️

[ilan-gold]

Can you add a release note explaining this a bit? Maybe a link to something like how you discovered this?

Also, it this something we should be doing globally?

Also, what if this crshes before you reset?