Update proxying-api-requests-in-development.md to use non-depricated format

Trillium S
2023-03-12T17:52:31Z

### Is your proposal related to a problem? The guide in [proxying-api-requests-in-development.md](https://create-react-app.dev/docs/proxying-api-requests-in-development/) uses a depricated webpack format for creating a dev server. When developing locally, leads to warnings

Warnings:

### Describe the solution you'd like Update the example file to create a dev server without warnings (at the time of writing I don't know what that is). ### Describe alternatives you've considered Add a warning on the page saying this method of creating a dev server is depricated ### Additional Context [Webpack middlewares](https://webpack.js.org/configuration/dev-server/#devserversetupmiddlewares) has instructions on this