cupy has scipy.ndimage.label -> use it for STO segmenters?

[paulmueller]

https://docs.cupy.dev/en/v13.1.0/reference/generated/cupyx.scipy.ndimage.label.html

[paulmueller]

It would be important to do a benchmark before implementing it. Since not all systems have an NVIDIA GPU, we also have to keep the fallback to scipy.ndimage.label, probably via a cached function getter.