chore(deps): update actions/checkout action to v4

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v3 -> v4

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Release Notes

actions/checkout (actions/checkout)

v4

Compare Source

• Check out other refs/* by commit if provided, fall back to ref by @​orhantoy in https://github.com/actions/checkout/pull/1924

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Configuration

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.62%. Comparing base (1fe37c7) to head (a788e8b).
Report is 4 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #126      +/-   ##
==========================================
- Coverage   77.75%   73.62%   -4.13%     
==========================================
  Files           9        9              
  Lines         436      436              
==========================================
- Hits          339      321      -18     
- Misses         97      115      +18     

Flag	Coverage Δ
os-macOS-12	?
os-ubuntu-latest	?
os-windows-latest	73.62% <ø> (ø)
py-3.10	73.62% <ø> (-4.13%)	⬇️
py-3.11	?
py-3.8	73.79% <ø> (-4.14%)	⬇️
py-3.9	?
unittests	73.62% <ø> (-4.13%)	⬇️

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