Fix Downgrade.yml

[ranocha]

Downgrade has never passed after being introduced in #192 and fixing some issues in #194

[ChrisRackauckas]

no, these are right https://github.com/SciML/SciMLBase.jl/blob/master/.github/workflows/Downgrade.yml

[ranocha]

Yeah, I just wanted to see whether the Compat.jl compatibilitily issues with Aqua.jl would be fixed by this.

[ChrisRackauckas]

QA tests should be in a separate test group. But it seems it has issues:

 └─restricted by compatibility requirements with Compat [34da2185] to versions: [0.1.0-0.4.11, 0.5.0] or uninstalled — no versions left
   └─Compat [34da2185] log:
     ├─possible versions are: 1.0.0-4.18.0 or uninstalled
     └─restricted to versions 2.2.1 by an explicit requirement, leaving only versions: 2.2.1

That probably shouldn't be to v1 😅 so there's some dependencies to fix.

But from looking at the PR, no the CI script seems right the dependencies just have real issues to fix.

[ranocha]

As far as I understood from the logs, the additional constraint that makes it fail comes from Aqua.jl...