Revert "[vbmc] Install python-dateutil"
Revert "[vbmc] Install python-dateutil"

The reason for the workaround was a missing dependency
in pyghmi 1.5.0.
Luckily, after merging https://review.opendev.org/#/c/698407/,
which adds the missing dependency, pyghmi 1.5.1 was created
a few hours ago, thus making this obsolete.

This reverts commit 1615ecc6d1a2bb290859f58c9eebcb116b6a657d.

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared