remove unnecessary babel.config.js in react native web example

[nissy-dev]

Documentation / Examples

Based on necolas/react-native-web#2217, the babel-plugin-react-native-web is not necessary. Therefore, I remove babel.config.js and npm package from package.json. This modification will improve build performance and bundle size.

• Make sure the linting passes by running pnpm build && pnpm lint
• The "examples guidelines" are followed from our contributing doc

[nissy-dev]

@ijjk I would like to review this PR 🙇 I'm a creator of swc-plugin-react-native-web, but I'm in trouble because many users uses it referencing this example settings and reports an error to my repo.

In many cases, users doesn't need to use babel plugin and swc plugin.

[ijjk]

Sounds good to remove this as it shouldn't be recommended by default, thanks!