[Bugfix] Fix LongCat TeaCache CFG negative-branch guidance kwargs (#6181)

Signed-off-by: Yifan Zong <yzong@redhat.com>

tests/model_tests/diffusion/model_settings.py

@@ -54,6 +54,16 @@ DIFFUSION_TEST_SETTINGS = {
         builder=diff_model_builders.tiny_qwen_image_builder,
         supported_tasks=[DiffusionTasks.TEXT_TO_IMAGE],
     ),
+    "LongCatImagePipeline": DiffusionModelTestOpts(
+        model="meituan-longcat/LongCat-Image",
+        builder=diff_model_builders.tiny_longcat_image_builder,
+        supported_tasks=[DiffusionTasks.TEXT_TO_IMAGE],
+        extra_test_groups=[
+            [DiffusionAccs.TEA_CACHE],
+            [DiffusionAccs.SEQUENCE_PARALLEL, DiffusionAccs.CACHE_DIT, DiffusionAccs.LAYERWISE_OFFLOAD],
+            [DiffusionAccs.CFG_PARALLEL, DiffusionAccs.TENSOR_PARALLEL, DiffusionAccs.CPU_OFFLOAD],
+        ],
+    ),
     "FluxPipeline": DiffusionModelTestOpts(
         model="black-forest-labs/FLUX.1-schnell",
         builder=diff_model_builders.tiny_flux_builder,