The Vagrant box of Leap 15.3 doesn't contain the repo data of the included
repositories, so the repo data has to be downloaded on the first use.

I understand, that the box itself should be as small as possible and contain
only a minimum set of packages / data. But as the purpose of Vagrant is to
increase development productivity by providing out-of-the-box usable VMs as
starting points, and the usage of zypper in an openSUSE Vagrant box is very
common (I take that for common), I propose to do a zypper refresh in the build
process of the Vagrant box.

This issue has been tightened with Leap 15.3, as it contains the sle-repository
which - in my observation - doesn't provide the throughput as known from the
other repositorys.
Currently, while the oss and non-oss repodata is downloading at my location
with 10MiB/s, the repodata for sle [1] is downloading with 50KiB/s.

[1]
http://download.opensuse.org/update/leap/15.3/sle/repodata/e17de7227675bcd95aa7bca3ec04bb3f87aea691f3a95896cc6322210932a3e2-primary.xml.gz