[Examples] Fix type-casting issue in the ControlNet training script (#2994)

* fix: norm group test for UNet3D.

* fix: type-casting issue in controlnet training.

examples/controlnet/train_controlnet.py

@@ -972,8 +972,10 @@ def main(args):
                     noisy_latents,
                     timesteps,
                     encoder_hidden_states=encoder_hidden_states,
-                    down_block_additional_residuals=down_block_res_samples,
-                    mid_block_additional_residual=mid_block_res_sample,
+                    down_block_additional_residuals=[
+                        sample.to(dtype=weight_dtype) for sample in down_block_res_samples
+                    ],
+                    mid_block_additional_residual=mid_block_res_sample.to(dtype=weight_dtype),
                 ).sample
 
                 # Get the target for loss depending on the prediction type