.gitlab-ci.yml: Ignore vulnerability GHSA-xqrq-4mgf-ff32
Vulnerability GHSA-xqrq-4mgf-ff32 (https://github.com/advisories/GHSA-xqrq-4mgf-ff32) is not concerning as we do not manipulate files from unknown origin that are not also the origin of code (e.g. PyPI packages).