Dockerfile: Use CI image v0.28.6 as base image#20

stephanosio merged 1 commit intozephyrproject-rtos:mainzephyrproject-rtos/docker-ci-repo-cache:mainfrom

stephanosio:base-v0.28.6stephanosio/zephyr-docker-ci-repo-cache:base-v0.28.6Copy head branch name to clipboard