Add test of new dumps

Problem/Motivation

Over in #3414563-51: Add new 10.3.x database dump fixtures, without modules deprecated for removal in 11.x → catch suggested adding a test;

I think we should create a follow-up to ensure we have a test on 10.3.x using the new dumps just to make sure everything is working as expected.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet