[Refactor][CI] Reorganize test tree, and move slow e2e to weekly (#4951)

Signed-off-by: wangyu <410167048@qq.com>

tests/diffusion/quantization/test_quantization_quality.py

@@ -431,6 +431,8 @@ def _free_gpu_memory():
 # ---------------------------------------------------------------------------
 
 
+@pytest.mark.core_model
+@pytest.mark.cpu
 def test_benchmark_generate_image_unwraps_nested_omni_request_output(monkeypatch):
     from benchmarks.diffusion.quantization_quality import _generate_image as benchmark_generate_image
     from vllm_omni.outputs import OmniRequestOutput