GitLab

Hydra env update
Closes https://github.com/MIC-DKFZ/nnDetection/issues/88

Update the `env:` notation to `oc.env:` which is supported in newer hydra versions.

Update the `env:` notation to `oc.env:` which is supported in newer hydra versions.

Check if instance class is defined in metadata

fix index in dataloading when object is larger than patch

fix: downgrading torchmetrics due to import error

`remove_modality=True` --> `remove_modality=False`

Fix raw_splitted mention and explicit python version in docs.