ificity
        >>> target = tensor([2, 1, 0, 0])
        >>> preds = tensor([[0.16, 0.26, 0.58],
        ...                 [0.22, 0.61, 0.17],
        ...                 [0.71, 0.09, 0.20],
        ...                 [0.05, 0.82, 0.13]])
        >>> multiclass_specificity(preds, target, num_classes=3)
        tensor(0.8889)
        >>> multiclass_specificity(preds, target, num_classes=3, average=None)
        tensor([1.0000, 0.6667, 1.0000])

    Example (multidim tensors):
        >>> from torchmetrics.functional.classification import multiclass_specificity
        >>> target = tensor([[[0, 1], [2, 1], [0, 2]], [[1, 1], [2, 0], [1, 2]]])
        >>> preds = tensor([[[0, 2], [2, 0], [0, 1]], [[2, 2], [2, 1], [1, 0]]])
        >>> multiclass_specificity(preds, target, num_classes=3, multidim_average='samplewise')
        tensor([0.7500, 0.6556])
        >>> multiclass_specificity(preds, target, num_classes=3, multidim_average='samplewise', average=None)
        tensor([[0.7500, 0.7500, 0.7500],
                [0.8000, 0.6667, 0.5000]])

    r.