Use "puppeteer-core" instead of full "puppeteer" NPM package (#1486)

## Problem

- The full "puppeteer" NPM package also takes care of downloading and
managing the web browsers.
- But as we use the system browser we do not need this functionality.

## Solution

- Installing just the "puppeteer-core" package makes the NPM bundle a
little bit smaller.
- See more details in https://pptr.dev/guides/installation

## Testing

- Tested manually