Update running-tests.md (#7659)

Author: weyert

docusaurus/docs/running-tests.md

@@ -204,7 +204,7 @@ import App from './App';
 
 it('renders welcome message', () => {
   const { getByText } = render(<App />);
-  expect(getByText('Welcome to React')).toBeInTheDocument();
+  expect(getByText('Learn React')).toBeInTheDocument();
 });
 ```