Set main_input_name in StableDiffusionSafetyChecker to "clip_input" (#7500)

FlaxStableDiffusionSafetyChecker sets main_input_name to "clip_input".
This makes StableDiffusionSafetyChecker consistent.
Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
Co-authored-by: YiYi Xu <yixu310@gmail.com>

src/diffusers/pipelines/stable_diffusion/safety_checker.py

@@ -31,6 +31,7 @@ def cosine_distance(image_embeds, text_embeds):
 
 class StableDiffusionSafetyChecker(PreTrainedModel):
     config_class = CLIPConfig
+    main_input_name = "clip_input"
 
     _no_split_modules = ["CLIPEncoderLayer"]