build: Update actions/checkout action to v4

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v2 -> 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

v3

Compare Source

• Fix: Mark test scripts with Bash'isms to be run via Bash
• Add option to fetch tags even if fetch-depth > 0

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Configuration

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[codecov-commenter]

Codecov Report

Merging #172 (bf4548e) into main (d41a235) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##              main      #172   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            2         2           
  Lines          100       100           
  Branches        18        18           
=========================================
  Hits           100       100           

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