Could the `get_namespace` helper be replaced by `array_api_compat.array_namespace`?

[paddyroddy]

Add your issue here

See https://data-apis.org/array-api-compat/helper-functions.html#array_api_compat.array_namespace. I'm pretty sure our function is doing the same thing essentially. I'm having to extend our current one, again, in #597.

[paddyroddy]

More specifically, their implementation looks like this https://github.com/data-apis/array-api-compat/blob/21aa31b7f89a053c8e657837e6f6a9eab2fe9b3d/array_api_compat/common/_helpers.py#L488-L653. You can see complex this can get when trying to handle the case of whether one of the inputs is, for example, float | Array. In #597 I was having to handle this case (having already raised #613), so I wonder if we could simplify things and use this array-api-compat function.

[paddyroddy]

Downside being that users would need the array-api-compat dependency