github: Update to checkout@v3

github: Update to checkout@v3

Update the checkout action to v3.  This is to appease the
following warning:

	Node.js 12 actions are deprecated. Please update the
	following actions to use Node.js 16: actions/checkout@v2,
	actions/setup-python@v2. For more information see:
	https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/.

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
Reviewed-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>