Cleanup TorchVision related functions (#18790)

ultralytics/cfg/models/11/yolo11-cls-resnet18.yaml

@@ -6,18 +6,11 @@
 
 # Parameters
 nc: 10 # number of classes
-scales: # model compound scaling constants, i.e. 'model=yolo11n-cls.yaml' will call yolo11-cls.yaml with scale 'n'
-  # [depth, width, max_channels]
-  n: [0.33, 0.25, 1024]
-  s: [0.33, 0.50, 1024]
-  m: [0.67, 0.75, 1024]
-  l: [1.00, 1.00, 1024]
-  x: [1.00, 1.25, 1024]
 
 # ResNet18 backbone
 backbone:
   # [from, repeats, module, args]
-  - [-1, 1, TorchVision, [512, "resnet18", "DEFAULT", True, 2]] # truncate two layers from the end
+  - [-1, 1, TorchVision, [512, resnet18, DEFAULT, True, 2]] # truncate two layers from the end
 
 # YOLO11n head
 head: