chore(deps): update actions/checkout action to v6

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v4 -> v6

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Release Notes

actions/checkout (actions/checkout)

v6

Compare Source

v5

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 91.26%. Comparing base (0aa6dd7) to head (ec70868).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2421      +/-   ##
==========================================
- Coverage   91.28%   91.26%   -0.02%     
==========================================
  Files         192      192              
  Lines       26184    26184              
==========================================
- Hits        23901    23898       -3     
- Misses       2283     2286       +3     

see 5 files with indirect coverage changes

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