We have a bunch of BlueSpice* extensions that require an ElasticSearch service to be running. For those extensions Selenium-Tests in the CI will most likely fail. We have set up our own internal Selenium-Tests for those extensions. Therefore those tests can be disabled on the WMF CI.
There is already a commit that just needs to be merged: https://gerrit.wikimedia.org/r/c/integration/config/+/624632