Don't add a PR comment for changes to ignored packages

[mikenikles]

Let's take a monorepo with the following structure:

.
└── packages
    ├── a
    ├── b
    └── c

Packages a and b have "private": true set in their package.json. Only package c gets published to NPM and benefits from Changesets.

When team members modify packages a and b, Changesets adds a comment to their PRs "⚠️ No Changeset found".

Is there a way to configure the Changesets GitHub action so it only posts comments to PRs when the PR contains changes for a package that is published to NPM?