[Tests] add slow and nightly markers to sd3 lora integation. (#10458)

add slow and nightly markers to sd3 lora integation.

tests/lora/test_lora_layers_sd3.py

@@ -29,9 +29,11 @@ from diffusers import (
 from diffusers.utils import load_image
 from diffusers.utils.import_utils import is_accelerate_available
 from diffusers.utils.testing_utils import (
+    nightly,
     numpy_cosine_similarity_distance,
     require_peft_backend,
     require_torch_gpu,
+    slow,
     torch_device,
 )
 
@@ -126,6 +128,8 @@ class SD3LoRATests(unittest.TestCase, PeftLoraLoaderMixinTests):
         pass
 
 
+@slow
+@nightly
 @require_torch_gpu
 @require_peft_backend
 class LoraSD3IntegrationTests(unittest.TestCase):