Update actions/checkout action to v4.2.1 (release/4.0.x)

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	patch	v4.2.0 -> v4.2.1

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Release Notes

actions/checkout (actions/checkout)

### [`v4.2.1`](https://redirect.github.com/actions/checkout/blob/HEAD/CHANGELOG.md#v421) [Compare Source](https://redirect.github.com/actions/checkout/compare/v4.2.0...v4.2.1) - 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)

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

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• [ ] If you want to rebase/retry this PR, check this box

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