tests(anaconda-iso): use --location for direct kernel boot

Switch virt-install from --cdrom to --location with explicit
kernel/initrd paths to enable direct kernel boot and serial console
output during anaconda installation. Extract the ISO label
dynamically with blkid for inst.stage2 and inst.ks arguments.

This fixes the issue where --cdrom boot through the ISO GRUB gave
no serial console visibility and anaconda silently failed to install
in CI environments.

Assisted-by: Claude Opus 4.6 <noreply@anthropic.com>"
Signed-off-by: Paul Whalen <pwhalen@fedoraproject.org>

Author: Paul Whalen

tests/greenboot-bootc-anaconda-iso.sh

@@ -302,14 +302,17 @@ greenprint "💾 Create vm qcow2 files for ISO installation"
 LIBVIRT_IMAGE_PATH_UEFI=/var/lib/libvirt/images/${TEST_UUID}-disk.qcow2
 sudo qemu-img create -f qcow2 "/var/lib/libvirt/images/${TEST_UUID}-disk.qcow2" 10G
 sudo restorecon -Rv /var/lib/libvirt/images/
+ISO_LABEL=$(blkid -o value -s LABEL /var/lib/libvirt/images/install.iso)
+greenprint "ISO label: ${ISO_LABEL}"
 sudo virt-install  --name="${TEST_UUID}-uefi"\
                    --disk path="${LIBVIRT_IMAGE_PATH_UEFI}",format=qcow2 \
                    --ram 3072 \
                    --vcpus 2 \
                    --network network=integration,mac=34:49:22:B0:83:30 \
                    --os-type linux \
                    --os-variant ${OS_VARIANT} \
-                   --cdrom "/var/lib/libvirt/images/install.iso" \
+                   --location "/var/lib/libvirt/images/install.iso",kernel=images/pxeboot/vmlinuz,initrd=images/pxeboot/initrd.img \
+                   --extra-args "console=ttyS0,115200 inst.stage2=hd:LABEL=${ISO_LABEL} inst.ks=hd:LABEL=${ISO_LABEL}:/osbuild.ks" \
                    --boot ${BOOT_ARGS} \
                    --graphics none \
                    --serial file,path=${CONSOLE_LOG} \