Migrating Yarn 1 to 4 in an Nx Monorepo

With just one migration, we reduced the execution time of yarn install on our CI from ~110s to ~25s. While also removing legacy patching with postinstall and by also keeping behaviour close enough to Yarn 1 to ensure a safe migration. At Wecasa, our frontend lives in a large Nx monorepo (web + mobile apps) and we were still running on Yarn 1.22.0. It worked well for a while, but at some point the dependency installation became a bottleneck on our CI. And our patch workflow (patch-package + posti