Remove etc-hosts DIB element

the etc-hosts DIB element was previously used to inject config for the
old sms pulp, which is no longer used

Author: Alex-Welsh

etc/kayobe/stackhpc-overcloud-dib.yml

@@ -25,7 +25,6 @@ stackhpc_overcloud_dib_elements:
   - "cloud-init-datasources"
   - "{% if os_distribution == 'rocky' %}selinux-permissive{% endif %}"
   - "enable-serial-console"
-  - "{% if kayobe_environment == 'ci-builder' %}etc-hosts{% endif %}"
   - "vm"
   - "block-device-efi"
   - "cloud-init"