`prevent_leaky_tests = false` results in failure

Unfortunately, we can't yet run with `prevent_leaky_tests = false` (which could be a decent bit faster) because we occasionally define global constants, which clash with local variables:

```julia
Spaces - serial CPU DSS: Error During Test at none:1
Got exception outside of a @test
LoadError: cannot declare Main.device constant; it already has a value
Stacktrace:
[1] top-level scope
@ ~/Dropbox/Caltech/work/dev/CliMA/ClimaCore.jl/test/Spaces/ddss1.jl:21
[2] include(fname::String)
@ Base.MainInclude ./client.jl:489
...
```

Start by examining test/Spaces/ddss1.jl around line 21 and reproduce the failure with prevent_leaky_tests = false. Trace the conflicting Main.device declaration and identify the test behavior needed for the suite to run without constant/local-variable clashes. Done means the affected test path completes successfully with that setting disabled.

Written by the indexing model from the issue text.