Revert "Enable AUM tests for amd64 and arm64"

This reverts commit d8db26c9 which was introduced to see how things would work. Apparently we still have some road to do before being able to properly turn on the tests on all the platforms since they were all failing.

Among others, https://phabricator.apertis.org/T6446 and https://phabricator.apertis.org/T6444 have been identified during this experiment.