fix: add type ignore comment for mypy no-any-return in utils.py

Signed-off-by: Rusheel Sharma <rusheelhere@gmail.com>

Author: Rusheel86

monai/metrics/utils.py

@@ -116,7 +116,7 @@ def create_ignore_mask(y: torch.Tensor, ignore_index: int | None) -> torch.Tenso
     num_classes = y.shape[1]
     if 0 <= ignore_index < num_classes:
         # Valid class index: exclude that channel
-        return 1.0 - y[:, ignore_index : ignore_index + 1]
+        return 1.0 - y[:, ignore_index : ignore_index + 1] # type: ignore[no-any-return]
     else:
         # Sentinel value: exclude where all channels are zero
         return (y.sum(dim=1, keepdim=True) > 0).float()