ci: install findutils in dockerfile.test
ci: install findutils in dockerfile.test

currently getting find command not found
and xargs command not found when we run
the dockerfile.test. installing findutils
to fix it.

Signed-off-by: Madhu Rajanna <60fbf37a92c2a0908e31296d18dadbec5a4dae17@gmail.com>

ceph/ceph-csi,ceph/ceph-csi,ceph/ceph-csi,ceph/ceph-csi