Fix minor bug in SD3 img2img test (#8779)

fix minor bug in sd3 img2img

Author: a-r-r-o-w

tests/pipelines/stable_diffusion_3/test_pipeline_stable_diffusion_3_img2img.py

@@ -108,7 +108,6 @@ def get_dummy_components(self):
 
     def get_dummy_inputs(self, device, seed=0):
         image = floats_tensor((1, 3, 32, 32), rng=random.Random(seed)).to(device)
-        image = image / 2 + 0.5
         if str(device).startswith("mps"):
             generator = torch.manual_seed(seed)
         else: