Overrides do no work in PNPM monorepo

[jelhan]

PNPM supports pnpm.overrides and resolutions only at the root of a project. Ember Try sets it at the closest package.json. In a typical setup of a v2 addon that's the "test-app" package. That does not have any affect. Ember Try must set it in the package.json at the workspace root.

Likely there is a second bug: Ember Try sets overrides at the root of the package.json. That's correct for NPM. But I think for PNPM it must go into a pnpm member. This is an example taken from PNPM documentation:

{
  "dependencies": {
    "foo": "^1.0.0"
  },
  "pnpm": {
    "overrides": {
      "foo": "$foo"
    }
  }
}

But Ember Try generates the following, which is valid for NPM but does not fit with PNPM documentation:

{
  "dependencies": {
    "foo": "^1.0.0"
  },
  "overrides": {
    "foo": "$foo",
  }
}