lorax: include kernels downloaded from Fedora repository

Do it by manually extracting packages from pungi cache instead of
redownloading, because we can't access yum configuration (repositories,
gpg keys etc) here, so it would be even more hacky...

All this is needed because pungi does not support including multiple
versions of a single package.

lorax-templates-qubes/templates/x86.tmpl

@@ -31,6 +31,8 @@ install boot/memtest* ${BOOTDIR}/memtest
 mkdir ${EXTRAKERNELS}
 # bypass "chroot" enforced by Lorax parser
 install ../../../../yum/qubes-dom0/rpm/kernel-[0-9]*rpm ${EXTRAKERNELS}
+# include kernels downloaded from Fedora repositories
+install ../../../../../../../../var/cache/pungi/fedora*/packages/kernel-[0-9]*rpm ${EXTRAKERNELS}
 
 ## install kernels
 mkdir ${KERNELDIR}