Update prediction to use cyto-dl==0.4.1

[yrkim98]

• src/allencell_ml_segmenter/prediction/model.py: Changed where we grab prediction outputs to display: now saved in seg
• src/allencell_ml_segmenter/services/prediction_service.py: Channel override changed to input_channel, also checking for None explicitly so a falsy value (like channel==0) still overrides the config.
• Test updates to reflect these changes