The v2 implementation uses Node 12, which is end-of-life on April 30, 2022.
See https://nodejs.org/en/about/releases/. Update to v3, which is based on
Node 16 whose support lasts until April 30, 2024.
This updates all the deploy scripts and the deploy workflow.
The deploy workflow now runs the metadata collector to collect the lint
documentation. It also changes the files that are checked out in the
deploy workflow from master and adds an explanation why we have to do
this.