RFR: 8315863: [GHA] Update checkout action to use v4

Thu Sep 7 15:59:39 UTC 2023

On Thu, 7 Sep 2023 14:47:41 GMT, Christian Stein <cstein at openjdk.org> wrote:

> Please review this change to update all workflows to use `actions/checkout at v4`.
> 
> Find the associated release notes here: https://github.com/actions/checkout/releases/tag/v4.0.0

Mainly because the underlying Node version used by `actions/checkout at v3` will reach EOL soon:

Copied from https://github.com/actions/checkout/pull/1436
> Node12 was deleted from runner. Node20 was added to Actions Runner on v2.308.0.
> Node16 has en end of life on 11 Sep 2023.

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PR Comment: https://git.openjdk.org/jdk/pull/15620#issuecomment-1710406436