Array API: locate the source of __array__(copy=...) DeprecationWarnings in CuPy runs

### Problem

#912 reports 15+ tests emitting:

> `DeprecationWarning: __array__ implementation doesn't accept a copy keyword, so passing copy=False failed...`

ccdproc itself defines no `__array__` method anywhere in the package (verified by grep), so the offending implementation lives upstream — most likely astropy's `NDData`/`CCDData`, `astropy.units`, or the CuPy interop layer.

### Task

- Run the CuPy (or proxy-backend) suite with `-W error::DeprecationWarning` to turn these into hard failures with full tracebacks.
- Identify which class's `__array__` lacks the numpy-2 `copy` keyword.
- File the fix upstream (link it from #940) or work around it locally if it is in the wrapper's interaction with astropy.

---
Found during a review of the array API implementation from #885; follow-up to #909 / #912.

Run the CuPy or proxy-backend suite with -W error::DeprecationWarning and use the full traceback to identify the upstream class whose __array__ lacks the NumPy 2 copy keyword. Confirm whether the issue is in the wrapper's interaction with astropy, then file the upstream fix linked from #940 or document a local workaround.

Written by the indexing model from the issue text.