Update testing quite with new demos

[jhdark]

With 6 new demos, we need to add these cases to the CI testing.

It might be worth investigating whether there is a neat way to automate testing the whole folder rather than testing each file individually. But @RemDelaporteMathurin probably already looked into that, I imagine

[RemDelaporteMathurin]

I haven't looked into that yet but yes we need it. I was just waiting for all the new PRs to be merged