ISO testing doesn't require the emulated firmware's PXE stack. For UEFI, it only disable iPXE in favor of EDK II network stack. https://github.com/tianocore/tianocore.github.io/wiki/EDKII-Network-Over-QEMU#verification-result
Various bash script improvements.
scripts/run_archiso.sh: A script to run a built archiso image using qemu. It can run the image on an emulated BIOS (using seabios) or UEFI (using edk2-ovmf) system. .gitlab-ci.yml: Adding scripts/run_archiso.sh to shellcheck call. Closes #28