test cases not executed in standalone CI

The plotting test currently fails in the cmake_standalone_test, see e.g. here and the lines below [1]. This seems to be the case after the following MR, where the plotting test was not executed on master and hence no artifacts for the plotting are uploaded that any new commit could compare to.

[1]
16: FAILED (failures=1) 16: 0:00:19 Searching for jobs and artifacts of last master parent (2333a8c1). 16: 0:00:21 Found job 3737673 for commit 2333a8c1. 16: 0:00:21 Artifacts are downloaded to directory "artifacts_3737673/plotting-artifacts". 16: 0:00:21 Comparing .C files. 16: 0:00:21 Artifacts folder with plots does not exist (artifacts_3737673/plotting-artifacts/referencePlots).