[PATCH] workflow: update to checkout at v3

[Simon Horman]

On Fri, Oct 21, 2022 at 05:27:57PM +0200, Simon Horman wrote:
> Use to checkout at v3 instead of checkout at v2
> as the latter uses Node.js 12 actions which are deprecated.
> 
> https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/
> 
> Signed-off-by: Simon Horman <horms at kernel.org>

Applied