fix: minor typo in docstring (#5961)

src/diffusers/pipelines/pixart_alpha/pipeline_pixart_alpha.py

@@ -662,7 +662,7 @@ class PixArtAlphaPipeline(DiffusionPipeline):
             timesteps (`List[int]`, *optional*):
                 Custom timesteps to use for the denoising process. If not defined, equal spaced `num_inference_steps`
                 timesteps are used. Must be in descending order.
-            guidance_scale (`float`, *optional*, defaults to 7.0):
+            guidance_scale (`float`, *optional*, defaults to 4.5):
                 Guidance scale as defined in [Classifier-Free Diffusion Guidance](https://arxiv.org/abs/2207.12598).
                 `guidance_scale` is defined as `w` of equation 2. of [Imagen
                 Paper](https://arxiv.org/pdf/2205.11487.pdf). Guidance scale is enabled by setting `guidance_scale >