Fix type of force_upcast to bool (#12046)

Author: BerndDoser

src/diffusers/models/autoencoders/autoencoder_kl.py

@@ -90,7 +90,7 @@ def __init__(
         shift_factor: Optional[float] = None,
         latents_mean: Optional[Tuple[float]] = None,
         latents_std: Optional[Tuple[float]] = None,
-        force_upcast: float = True,
+        force_upcast: bool = True,
         use_quant_conv: bool = True,
         use_post_quant_conv: bool = True,
         mid_block_add_attention: bool = True,