Fix: Override __call__ method in PixArtSigmaPipeline

The patched pipeline_pixart_alpha_call function was defined but never
assigned to the pipeline class. Added __call__ assignment to use the
patched call method that calls self.classify_height_width_bin() instead
of self.image_processor.classify_height_width_bin().

scripts/diffusers_patches.py

@@ -493,6 +493,9 @@ class PixArtSigmaPipeline(PixArtAlphaPipeline):
         
         return image
 
+    # Override __call__ with the patched version
+    __call__ = pipeline_pixart_alpha_call
+
 
 def pixart_sigma_init_patched_inputs(self, norm_type):
     assert self.config.sample_size is not None, "Transformer2DModel over patched input must provide sample_size"