Bump node-fetch and puppeteer-core

Bumps [node-fetch](https://github.com/node-fetch/node-fetch) to 2.6.12 and updates ancestor dependency [puppeteer-core](https://github.com/puppeteer/puppeteer). These dependencies need to be updated together.


Updates `node-fetch` from 2.6.1 to 2.6.12
- [Release notes](https://github.com/node-fetch/node-fetch/releases)
- [Commits](node-fetch/node-fetch@v2.6.1...v2.6.12)

Updates `puppeteer-core` from 10.4.0 to 20.8.3
- [Release notes](https://github.com/puppeteer/puppeteer/releases)
- [Changelog](https://github.com/puppeteer/puppeteer/blob/main/release-please-config.json)
- [Commits](puppeteer/puppeteer@v10.4.0...puppeteer-core-v20.8.3)

---
updated-dependencies:
- dependency-name: node-fetch
  dependency-type: indirect
- dependency-name: puppeteer-core
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>