remove node 18 mention (#1382)

Author: timdeschryver

docs/react-testing-library/example-intro.mdx

@@ -70,8 +70,6 @@ We recommend using the
 [Mock Service Worker (MSW)](https://github.com/mswjs/msw) library to
 declaratively mock API communication in your tests instead of stubbing
 `window.fetch`, or relying on third-party adapters.
-
-MSW requires Node.js 18 or later. 
 :::
 
 ```jsx title="__tests__/fetch.test.jsx"