Create a test for a dev release without a date

Problem/Motivation

In #3291893: Stub release for 10.1.x breaks 10.0.x tests in HEAD. we discovered that the stub release of 10.1.x messed with the installer test on 10.0.x.
We excluded dev-releases without a date to be processed to get around this problem.

To get HEAD of 10.0.x into a happy state as soon as possible we proceeded with that issue without a valid test case for the above.

This issue exists to get that valid test case in.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet