Investigate slow image build
Recently, wait:cng sometimes fails because of slow image build (example gitlab-org/release/tasks#7493 (closed)). @rpereira2 found sth in our metrics. I quote him below:
Looking at the duration of the CNG packager pipeline over the last few weeks, it looks like there was a big jump in pipeline duration around 31st October 1st Nov, and then again on 14th November.
The Y axis on the following graph represents duration in minutes.
We should check what happened then.