update all dependencies to @latest, drop node@8 CI testing, add node@16

[broofa]

Got paranoid after seeing this news and decided to update all our dependencies to the latest version of things.

npm run build and npm test appear to work.

Edit: npm run lint broke. Fixing this involved switching to @eslint/babel-parser, and then eslint --fix and prettier -w to patch formatting differences.

... and apparently jest@latest doesn't work with node@8. So I've updated our CI platforms to drop node 8 and add node 16.

Note: I don't know why Github is saying it needs the "ci (8.x) Expected" check here, since I removed node 8 from the node-versions in the ci.yml workflow. 😕

[ctavan]

@broofa you need to adjust the branch settings on GitHub for this repo since I marked all checks as mandatory.

I was tempted to update jest a couple of times in the past but then realized it would technically force us to drop node 8 support.

I do think we should finally drop node 8 support, but again, technically it will require us to do a major version bump…

[broofa]

Okay, removed node 8 from checks. Also renamed master to main.

[broofa]

@ctavan ping

[ctavan]

I'm generally fine with this change, but please make sure that when you squash and merge, the resulting commit message follows https://www.conventionalcommits.org/en/v1.0.0/ to produce a breaking change entry in the changelog (e.g. like daf72b8).

I also noticed that the README still needs an update in the summary where it still mentions Node 8.