Fix bf15/fp16 for pipeline_wan_vace.py

Author: SlimRG

src/diffusers/pipelines/wan/pipeline_wan_vace.py

@@ -526,7 +526,7 @@ def prepare_video_latents(
             latents = ((latents.float() - latents_mean) * latents_std).to(vae_dtype)
         else:
             mask = mask.to(dtype=vae_dtype)
-            mask = torch.where(mask > 0.5, 1.0, 0.0)
+            mask = torch.where(mask > 0.5, 1.0, 0.0).to(dtype=vae_dtype)
             inactive = video * (1 - mask)
             reactive = video * mask
             inactive = retrieve_latents(self.vae.encode(inactive), generator, sample_mode="argmax")