kata-deploy: realpath INCLUDE_ROOTFS for Docker

Run `realpath` on `INCLUDE_ROOTFS` so it is not required to provide a
full path. This simplifies the required GitHub Actions workflow, as
GitHub's `env` cannot use shell expansions, as well as the usability
overall.

Signed-off-by: Jakob Naucke <jakob.naucke@ibm.com>

tools/packaging/kata-deploy/local-build/kata-deploy-binaries-in-docker.sh

@@ -41,7 +41,7 @@ docker run ${TTY_OPT} \
 	--env SKOPEO="${SKOPEO:-}" \
 	--env UMOCI="${UMOCI:-}" \
 	--env AA_KBC="${AA_KBC:-}" \
-	--env INCLUDE_ROOTFS="${INCLUDE_ROOTFS:-}" \
+	--env INCLUDE_ROOTFS="$(realpath "${INCLUDE_ROOTFS:-}" 2> /dev/null || true)" \
 	-v "${kata_dir}:${kata_dir}" \
 	--rm \
 	-w ${script_dir} \