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

sgl-router/pyproject.toml

@@ -28,8 +28,3 @@ find = { where = ["py_src"] }
 # workaround for https://github.com/pypa/twine/issues/1216
 [tool.setuptools]
 license-files = []
-
-[[tool.setuptools-rust.ext-modules]]
-target = "sglang_router_rs"
-path = "Cargo.toml"
-binding = "PyO3"