Simplify Router arguments passing and build it in docker image (#9964)

sgl-router/setup.py

@@ -0,0 +1,21 @@
+import os
+
+from setuptools import setup
+from setuptools_rust import Binding, RustExtension
+
+no_rust = os.environ.get("SGLANG_ROUTER_BUILD_NO_RUST") == "1"
+
+rust_extensions = []
+if not no_rust:
+    rust_extensions.append(
+        RustExtension(
+            target="sglang_router_rs",
+            path="Cargo.toml",
+            binding=Binding.PyO3,
+        )
+    )
+
+setup(
+    rust_extensions=rust_extensions,
+    zip_safe=False,
+)