Cannot use average method 'none' in Dice meter

[CielAl]

🐛 Bug

In the docstring of
it states that average allows none or None input wherein a class-wise result will be reported. However the code here https://github.com/Lightning-AI/torchmetrics/blob/master/src/torchmetrics/classification/dice.py#L176 suggests that a ValueError will be raised and therefore average must be micro/macro/sample.

It appears that the value check is redundant considering the following line was added already.

        if average not in allowed_average:
            raise ValueError(f"The `average` has to be one of {allowed_average}, got {average}.")

To Reproduce

Steps to reproduce the behavior...

Code sample

Expected behavior

Environment

• TorchMetrics version (and how you installed TM, e.g. conda, pip, build from source):
• Python & PyTorch Version (e.g., 1.0):
• Any other relevant information such as OS (e.g., Linux):

Additional context

[github-actions]

Hi! thanks for your contribution!, great first issue!

[Borda]

seems to be related to #2282