Update actions/checkout action to v6

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v5 → v6

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Release Notes

actions/checkout (actions/checkout)

v6

Compare Source

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Configuration

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.66%. Comparing base (6d16f04) to head (f285179).

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #99   +/-   ##
=======================================
  Coverage   85.66%   85.66%           
=======================================
  Files           2        2           
  Lines         544      544           
=======================================
  Hits          466      466           
  Misses         78       78           

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