fix(auth): assert redirect_uris for pyright without coverage gap

Author: KirtiRamchandani

src/mcp/server/auth/handlers/register.py

@@ -92,14 +92,7 @@ async def handle(self, request: Request) -> Response:
             )
 
         redirect_uris = client_metadata.redirect_uris
-        if redirect_uris is None:
-            return PydanticJSONResponse(
-                content=RegistrationErrorResponse(
-                    error="invalid_client_metadata",
-                    error_description="redirect_uris is required",
-                ),
-                status_code=400,
-            )
+        assert redirect_uris is not None  # enforced by OAuthClientMetadata
 
         for redirect_uri in redirect_uris:
             try: