Rollback Prometheus update
Rollback Prometheus from 2.15.2 to 2.13.1 to fix asset build.
Prometheus 2.14.0 introduced a new UI which requires a react build. We will need to figure out how to handle this before we can update past 2.13.1.
Signed-off-by: Ben Kochie bjk@gitlab.com
Edited by GitLab Release Tools Bot