The previous release mistakenly distributed the wrong version
of node...

Very sad.

See https://github.com/cdr/code-server/issues/1710#issuecomment-646472716

- Instead we now use CentOS 7 for the static build to guarantee
  that we only depend on libc v2.17

- For macOS we now pull in a static node binary and bundle that instead.

More clear as discussed in PR.

Closes #1665

Much better test now as well.

The architecture specific jobs pull it in and then build releases.

Much faster!

Closes many issues that I'll prune after adding more docs
for users.