simplify the control logic for using shared experts fusion (#5504)

python/sglang/srt/layers/quantization/__init__.py

@@ -290,6 +290,7 @@ def monkey_patch_moe_apply(class_obj: "FusedMoEMethodBase"):
         apply_router_weight_on_input: bool = False,
         inplace: bool = True,
         no_combine: bool = False,
+        routed_scaling_factor: Optional[float] = None,
     ):
         assert activation == "silu"
         assert inplace and not no_combine