⬆️ Update actions/checkout action to v4

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v2 -> v4

:warning: MAJOR MAJOR MAJOR :warning:

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Release Notes

actions/checkout (actions/checkout)

### [`v4`](https://redirect.github.com/actions/checkout/blob/HEAD/CHANGELOG.md#v421) [Compare Source](https://redirect.github.com/actions/checkout/compare/v3...v4) - Check out other refs/\* by commit if provided, fall back to ref by [@​orhantoy](https://redirect.github.com/orhantoy) in [https://github.com/actions/checkout/pull/1924](https://redirect.github.com/actions/checkout/pull/1924) ### [`v3`](https://redirect.github.com/actions/checkout/blob/HEAD/CHANGELOG.md#v360) [Compare Source](https://redirect.github.com/actions/checkout/compare/v2...v3) - [Fix: Mark test scripts with Bash'isms to be run via Bash](https://redirect.github.com/actions/checkout/pull/1377) - [Add option to fetch tags even if fetch-depth > 0](https://redirect.github.com/actions/checkout/pull/579)

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