interrogate: Fix CLIP-interrogation on CPU

[Patryk27]

Currently, trying to perform CLIP interrogation on a CPU fails, saying:

RuntimeError: "slow_conv2d_cpu" not implemented for 'Half'

This merge request fixes this issue by detecting whether the target device is CPU and, if so, force-enabling --no-half and passing device="cpu" to clip.load() (which then does some extra tricks to ensure it works correctly on CPU).