Add missing license for router wheel (#2324)

Signed-off-by: Ata Fatahi <immrata@gmail.com>

rust/pyproject.toml

@@ -9,6 +9,7 @@ description = "SGLang router is a standalone module implemented in Rust to achie
 authors = [{name = "Byron Hsu", email = "byronhsu1230@gmail.com"}]
 requires-python = ">=3.8"
 readme = "README.md"
+license = { file = "LICENSE" }
 classifiers = [
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Rust",