Fix CI

Author: james77777778

keras_nlp/src/models/resnet/resnet_image_classifier.py

@@ -99,7 +99,7 @@ def __init__(
         # TODO: once preprocessor flow is figured out, this needs to be updated
         **kwargs,
     ):
-        head_dtype = head_dtype or self.backbone.dtype_policy
+        head_dtype = head_dtype or backbone.dtype_policy
 
         # === Layers ===
         self.backbone = backbone