workflow: update to checkout@v3

Use to checkout@v3 instead of checkout@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@kernel.org>
1 file changed