Post NPM publish sanity check workflow

[dphang]

Describe the solution you'd like

Add a workflow that could be run ~15 minutes after it detects a publish commit of a stable version. The reason for 15 minutes is since it may take some time to be available on npm after publishing.

This should be a quick sanity check to ensure that stable versions are actually not broken

• check that the test next-app can be deployed and optionally tests pass
• check that exact dependencies are used
• maybe we can also use npm publish --dry-run to do some pre-publish validations