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

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

tests/diffusion/models/ltx2/test_ltx2_transformer.py

@@ -9,6 +9,8 @@ from vllm_omni.diffusion.models.ltx2.ltx2_transformer import LTX2VideoTransforme
 
 pytestmark = [pytest.mark.core_model, pytest.mark.cpu]
 
+pytestmark = [pytest.mark.core_model, pytest.mark.diffusion, pytest.mark.cpu]
+
 
 def test_ltx_rms_norm_no_affine_matches_official_torch_module():
     norm = _make_rms_norm(8, eps=1e-6, elementwise_affine=False)