update dependency check

lightly/utils/dependency.py

@@ -46,13 +46,16 @@ def timm_vit_available() -> bool:
 
 @functools.lru_cache(maxsize=1)
 def torchvision_transforms_v2_available() -> bool:
-    """Checks if torchvision supports the transforms.v2 API.
+    """Checks if torchvision supports the v2 transforms API with the `tv_tensors`
+    module. Checking for the availability of the `transforms.v2` is not sufficient
+    since it is available in torchvision >= 0.15.1, but the `tv_tensors` module is
+    only available in torchvision >= 0.16.0.
 
     Returns:
         True if transforms.v2 are available, False otherwise
     """
     try:
-        from torchvision.tv_tensors import Mask
+        from torchvision import tv_tensors
     except ImportError:
         return False
     return True