chore(deps): update actions/checkout action to v4

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v3 -> v4

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[!WARNING] Some dependencies could not be looked up. Check the Dependency Dashboard for more information.

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Release Notes

actions/checkout (actions/checkout)

### [`v4`](https://togithub.com/actions/checkout/blob/HEAD/CHANGELOG.md#v400) [Compare Source](https://togithub.com/actions/checkout/compare/v3...v4) - [Support fetching without the --progress option](https://togithub.com/actions/checkout/pull/1067) - [Update to node20](https://togithub.com/actions/checkout/pull/1436)

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Configuration

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[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 88.22%. Comparing base (8800728) to head (b80c7e7).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #603 +/- ## ======================================= Coverage 88.22% 88.22% ======================================= Files 10 10 Lines 960 960 ======================================= Hits 847 847 Misses 88 88 Partials 25 25 ``` | [Flag](https://app.codecov.io/gh/open-feature/open-feature-operator/pull/603/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-feature) | Coverage Δ | | |---|---|---| | [unit-tests](https://app.codecov.io/gh/open-feature/open-feature-operator/pull/603/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-feature) | `88.22% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=open-feature#carryforward-flags-in-the-pull-request-comment) to find out more.