Fix react-native-razorpay test's JSX fragment usage

It now requires an explicit import of React in order to use JSX fragments.

Here is the Typescript 5.7 PR that introduced this error:

microsoft/TypeScript#59933

types/react-native-razorpay/react-native-razorpay-tests.tsx

@@ -1,3 +1,4 @@
+import * as React from "react";
 import { Button } from "react-native";
 import RazorpayCheckout, { ErrorResponse } from "react-native-razorpay";