maint: post-version bump version bump to 6.0.0
maint: post-version bump version bump to 6.0.0

Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

libvirt/libvirt,crobinso/libvirt,olafhering/libvirt,jfehlig/libvirt,zippy2/libvirt,fabianfreyer/libvirt,libvirt/libvirt,zippy2/libvirt,olafhering/libvirt,nertpinx/libvirt,jardasgit/libvirt,zippy2/libvirt,nertpinx/libvirt,libvirt/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,crobinso/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,jardasgit/libvirt,nertpinx/libvirt,jardasgit/libvirt,zippy2/libvirt,nertpinx/libvirt,crobinso/libvirt,olafhering/libvirt,libvirt/libvirt,olafhering/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,jardasgit/libvirt,jfehlig/libvirt,crobinso/libvirt