[Libguestfs] [PATCH libnbd CI] ci: Drop Fedora 33, add Fedora 35

Hi Martin, The pipeline failed, and I'm assuming this is because Fedora 33 is out of support. The log is not very helpful: https://gitlab.com/nbdkit/libnbd/-/jobs/1874368914 Also we don't seem to have lcitool in Fedora anywhere obvious, so instead I just updated the generated files directly. Also, wouldn't it be nice if we could specify "fedora:n" and "fedora:n-1" instead of having to update this every six months ... Rich.