Update buildah to 1.16.2

Changelog:

• Add(): fix handling of relative paths with no ContextDir
• copier.Get(): hard link targets shouldn't be relative paths

Run a few buildah commands:

• buildah from debian:buster
• buildah run debian-working-container apt update
• buildah run debian-working-container apt upgrade -y
• buildah run debian-working-container apt install curl -y
• buildah copy debian-working-container test.sh /local/bin/test.sh
• buildah run debian-working-container chmod +x /local/bin/test.sh
• buildah run /local/bin/test.sh
• buildah config --entrypoint "/local/bin/test.sh" debian-working-container
• buildah commit debian-working-container debian-test
• buildah images

Test image with podman:

• podman run debian-test
• podman run -it debian-test /bin/bash