Update actions/checkout action to v4.2.1

[renovate]

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

Compare Source

• Check out other refs/* by commit if provided, fall back to ref by @​orhantoy in https://github.com/actions/checkout/pull/1924

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