[2.18] Run 0100-dhclient-hooks if dhcpclient is enabled (#8658) (#8661)

* Run 0100-dhclient-hooks if dhcpclient is enabled (#8658)

If running Kubespray on static IP environments, a task was failed like:

  TASK [kubernetes/preinstall : Configure dhclient hooks for resolv.conf (RH-only)]
  fatal: [ak8s2]: FAILED! => {
    "changed": false, "checksum": "..",
    "msg": "Destination directory /etc/dhcp/dhclient.d does not exist"}

This adds a check for dhclientconffile for running 0100-dhclient-hooks to
run the task only if dhcpclient is enabled.

* Remove centos7 molecule while opensuse mirror is flaky

Co-authored-by: Florian Ruynat <16313165+floryut@users.noreply.github.com>