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

• Support fetching without the --progress option
• Update to node20

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Configuration

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[codecov]

Codecov Report

Merging #158 (d59d51c) into main (273362f) will increase coverage by 0.47%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #158      +/-   ##
==========================================
+ Coverage   88.67%   89.15%   +0.47%     
==========================================
  Files          16       16              
  Lines         848      848              
==========================================
+ Hits          752      756       +4     
+ Misses         96       92       -4     

see 2 files with indirect coverage changes