chore(deps): update actions/checkout action to v5

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v4 -> v5

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Release Notes

actions/checkout (actions/checkout)

v5

Compare Source

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Configuration

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[what-the-diff]

PR Summary

• Updated Action Versions
  The version of actions/checkout used in our system has been updated from v4 to v5. This improvement affects three different workflow files which control certain automated tasks in our project. The files involved are:
  • editorconfig-checks.yaml
  • nix-flake-check.yaml
  • nix-fmt-checks.yaml

With this change we can expect better performance and potentially new features for these workflows, enhancing the way we automate and manage our software processes.