Use Yarn 4

[Saadnajmi]

Please select one of the following

• [ ] I am removing an existing difference between facebook/react-native and microsoft/react-native-macos :thumbsup:
• [ ] I am cherry-picking a change from Facebook's react-native into microsoft/react-native-macos :thumbsup:
• [x] I am making a fix / change for the macOS implementation of react-native
• [ ] I am making a change required for Microsoft usage of react-native

Summary:

There's nothing preventing us from using yarn 4, and there are several long term benefits that could be had by being on the latest version of the package manager. Let's update! I ran the following steps:

1. Ran yarn set version berry locally
2. Set linker: "node-modules" in the .yarnrc.yml file
3. Ran yarn

An interesting side effect is that by running yarn now lints/formats all the package.json files in the mono repo. So that we don't maintain this extra diff, I'm opening https://github.com/facebook/react-native/pull/42256 to upstream theses formats to React Native.

Changelog:

[INTERNAL] [CHANGED] - Use Yarn 4 for the mono repo

Test Plan:

CI should pass. After all, running yarn should be the same.

[Saadnajmi]

I may wait to see if https://github.com/facebook/react-native/pull/42256 merges upstream first, so that we can pick the change up in a merge / cherry-pick it