[Rebase] Rebase to vllm 0.20.0 (#3232)

Signed-off-by: tzhouam <tzhouam@connect.ust.hk>
Signed-off-by: Zhou Taichang <tzhouam@connect.ust.hk>
Signed-off-by: Yuanheng Zhao <jonathan.zhaoyh@gmail.com>
Co-authored-by: Yuanheng Zhao <54058983+yuanheng-zhao@users.noreply.github.com>

vllm_omni/diffusion/models/wan2_2/patch_diffusers.py

@@ -9,6 +9,10 @@ from vllm_omni.diffusion.layers.norm import RMSNormVAE
 def patch_wan_rms_norm():
     """Patch diffusers Wan RMSNorm implementation with RMSNormVAE."""
 
-    for module_name, module in sys.modules.items():
+    # NOTE: iterate over a snapshot of sys.modules. `hasattr` can trigger lazy
+    # submodule imports (e.g. transformers' `_LazyModule.__getattr__`), which
+    # mutate sys.modules during iteration and raise
+    # `RuntimeError: dictionary changed size during iteration`.
+    for module_name, module in list(sys.modules.items()):
         if hasattr(module, "WanRMS_norm"):
             setattr(module, "WanRMS_norm", RMSNormVAE)