GH Docker Action cache repro

Repro for the long cache export GHA Docker issue

Related issue:

Some facts:

• Project based on monorepo from here: https://github.com/axeldelafosse/expo-next-monorepo-example
• It's a Next.js app with React Native Web
• The turbo prune command comes from TurboRepo and creates a out/ dir with Docker-friendly file structure, more on this in the docs
• Original repo has some more stuff, but it's irrelevant here so pruned as much as possible