Describe the issue:

The type hints for interp assert that the return dtype is a numpy array, but when the function is called with a scaler it gives a float. This raises some mypy errors.

Reproduce the code example:

>>> np.interp(0, [1, 2], [3, 4])
np.float64(3.0)

Error message:

my_code.py::123 error: Incompatible return value type (got "ndarray[Any, Any]", expected "float")  [return-value]

Python and NumPy Versions:

python: 3.12.2
numpy: 2.1.3

Runtime Environment:

No response

Context for the issue:

No response