Update black in pre-commit.

[grahamgower]

Closes #1223.

[grahamgower]

I'm not sure what the process is for developers after this gets merged. Maybe the installed pre-commit sees this change and autoupdates accordingly? In the worst case, something like pre-commit clean && pre-commit install -f might be needed by a developer (but possibly not until they change/add a line that uses the power operator!). @jeromekelleher do you know?

[codecov]

Codecov Report

Merging #1224 (94cc1d5) into main (6655f5e) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1224   +/-   ##
=======================================
  Coverage   99.56%   99.56%           
=======================================
  Files          98       98           
  Lines        3182     3182           
  Branches      414      414           
=======================================
  Hits         3168     3168           
  Misses          6        6           
  Partials        8        8           

Impacted Files	Coverage Δ
stdpopsim/catalog/AraTha/species.py	100.00% <ø> (ø)
stdpopsim/catalog/HomSap/species.py	100.00% <ø> (ø)
stdpopsim/catalog/HomSap/demographic_models.py	100.00% <100.00%> (ø)
stdpopsim/engines.py	100.00% <100.00%> (ø)
stdpopsim/qc/HomSap.py	100.00% <100.00%> (ø)
stdpopsim/slim_engine.py	99.76% <100.00%> (ø)

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[jeromekelleher]

LGTM

The update is pretty painless I think. I didn't notice any changes when it went through tskit/msprime, so I think it's probably fine to go ahead.

[grahamgower]

Cool, thanks Jerome.