Fix ValueError in test_process by copying input array

[mweinelt]

This fixes an error seen with NumPy 2.4:

    def test_process(data, converter_type, ratio=2.0):
        num_channels, input_data = data
        src = samplerate.Resampler(converter_type, num_channels)
>       src.process(input_data, ratio)
E       ValueError: cannot resize an array that references or is referenced
E       by another array in this way.
E       Use the np.resize function or refcheck=False

[mweinelt]

Makes it work on 3.13, but apparently insufficent for 3.14. I'm out of my depth here.