Investigate test failure TestGetSourceMount

Description

For the #v2022dev2 release, the new docker.io package fails in one of the tests, precisely TestGetSourceMount.

To progress further on the rebase, this proposed MR disables the failing test.

This task is about investigating the cause of the failure for the mentioned test.

==Acceptance criteria [] Investigate the cause of the failure for the test (TestGetSourceMount) on OBS [] Depending on the root-cause, patch the failing package. [] Submit patch upstream if the fix is generic.

Management data

This section is for management only, it should be the last one in the description.

Phabricator link: https://phabricator.apertis.org/T7852