python: Replace universal_newlines with text.

This is supported in Python ≥ 3.7.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

zerver/openapi/javascript_examples.py

@@ -20,7 +20,7 @@ def test_js_bindings(client: Client) -> None:
 
     output = subprocess.check_output(
         args=["node", "--unhandled-rejections=strict", "zerver/openapi/javascript_examples.js"],
-        universal_newlines=True,
+        text=True,
     )
     endpoint_responses = json.loads(output)