Test device support

[asmeurer]

Basic device support should be tested. In particular, we can test things like whether mixing devices properly raises an exception in all functions (this would be useful for the array-api-strict library, which implements this but it currently isn't tested). We can also test things like that the output device is equal to the input device.

[ev-br]

Cross-ref data-apis/array-api-strict#134

[crusaderky]

scipy/scipy#22756 for pattern on how to test device propagation from input to output

[crusaderky]

@tylerjereddy FYI