script/build-with-container: skip dnf cache dir volume mounts on docker

script/build-with-container: skip dnf cache dir volume mounts on docker

When using docker the --volume option is not available during build
(docker [buildx] build), unlike podman. Since passing these volumes must
be conditional on them being set up I see no way to handle this short of
just disabling the option on docker. Log the fact that it's being
skipped - the only other issue is that we pointlessly set up some dirs
and the build may be a bit slower.

Signed-off-by: John Mulligan <jmulligan@redhat.com>