It isn't clear from the 'check' target that the check succeeded

**Describe the bug**

It ends with:
```
Set::RelOp::ConstSSI::Union::Sup::0 ++
Set::RelOp::ConstSSI::Union::Sub::2 ++
Set::RelOp::ConstSSI::Union::Nq::2 ++
Set::RelOp::ConstSSI::Union::Sup::2 ++
Set::Dom::Dom::Gr::2 ++
```

**Suggested solution**
It should print: ```Checks succeeded```.

Start by locating the project's `check` target and run it to reproduce the current output. Update the check target so a successful run clearly prints `Checks succeeded`, then rerun it and confirm the success message appears.

Written by the indexing model from the issue text.