### Check existing issues - [x] I've verified that this request isn't described by any existing issues. ### Request [pnpm](https://pnpm.io/) is a faster, more modern alternative to npm that is growing in popularity for Node.js projects. ### The problem it solves This would be useful in snaps for codebases that use it, such as [signal-desktop](https://github.com/snapcrafters/signal-desktop/blob/candidate/snap/snapcraft.yaml).