Installing unpinned vega-lite package breaks Node 12 support

[0x2b3bfa0]

We're installing all the vega packages without any version pinning, and with methods other than package-lock.json 🙀

setup-cml/src/utils.js

Lines 35 to 37 in fbe9608

	`${sudo} npm install -g canvas vega vega-cli vega-lite @dvcorg/cml${
	version !== 'latest' ? `@${version}` : ''
	}`

Tests were failing for #38* because we depend on vega-lite and it's trying to use a nullish coalescing operator ?? on Node JS 12, but wasn't supported until 14.

See also vega/vega-lite#v5.0.0 release notes: no more ES5 builds.

---

* Tests were failing also for the master branch; we know it thanks to the scheduled tests introduced with #37.

[0x2b3bfa0]

Pinning behavior of actions/setup-node

The node-version input is optional. If not supplied, the node version from PATH will be used. However, it is recommended to always specify Node.js version and don't rely on the system one.

For information regarding locally cached versions of Node.js on GitHub hosted runners, check out GitHub Actions Virtual Environments.

[0x2b3bfa0]

Default Node JS version on GitHub Actions

GitHub Actions Virtual Environments are in Node 14 since 2020-11-02, as per actions/runner-images#1953 (comment), so supporting 12 is not neccessary anymore, but we're going to keep it around for compatibility.

[0x2b3bfa0]

Should we install vega and related packages?

• It looks like it might not be the case. See Remove vega related packages #8 for more information.

[DavidGOrtega]

We decided to include vega as far as I remember, it was removed for a while a then we came back