Remove gitlab-runner project from CHARTS_LIST file

With charts/gitlab-runner!72, we're changing the way of releasing GitLab Runner Helm Chart. With this, packages for GitLab Runner Helm Chart will be built and copied to S3 with release_chart job, triggered from Runner's Helm Chart pipeline. Because we want to publish only tagged versions, we don't want to package and publish charts from master branch in https://gitlab.com/charts/gitlab-runner.

This MR removes the gitlab-runner project from the list in CHARTS_LIST file. With this, test and pages jobs are no longer generating packages for it, so gitlab-runner starts being handled like gitlab chart.

Part of gitlab-org/gitlab-runner#3782 (closed)

Waits for charts/gitlab-runner!72 to be merged first.