Improve kolla-build.conf apt_preferences path

Author: Alex-Welsh

etc/kayobe/kolla/kolla-build.conf

@@ -4,7 +4,7 @@
 {# This tag should be updated when Ubuntu package repo snapshot versions are changed. #}
 {% if kolla_base_distro == 'ubuntu' %}
 base_tag = noble-20241118.1
-apt_preferences = /home/runner/_work/stackhpc-kayobe-config/stackhpc-kayobe-config/src/kayobe-config/etc/kayobe/environments/ci-builder/builder-apt-preferences
+apt_preferences = {{ lookup('env', 'KAYOBE_CONFIG_PATH') }}/environments/ci-builder/builder-apt-preferences
 {# Similarly pinning to Rocky 9 minor version used in our repos #}
 {% elif kolla_base_distro == 'rocky' %}
 base_tag = 9.{{ stackhpc_pulp_repo_rocky_9_minor_version }}