chore: add node.js v16 support

[dnalborczyk]

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

List any relevant issue numbers:

Description

[github-actions]

Thank you for your contribution! ❤️

You can try out this pull request locally by installing Rollup via

npm install dnalborczyk/rollup#node-16

or load it into the REPL:
https://rollupjs.org/repl/?pr=4071

[codecov]

Codecov Report

Merging #4071 (033cd23) into master (2bee261) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #4071   +/-   ##
=======================================
  Coverage   97.49%   97.49%           
=======================================
  Files         193      193           
  Lines        6818     6818           
  Branches     2002     2002           
=======================================
  Hits         6647     6647           
  Misses         84       84           
  Partials       87       87           

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[shellscape]

current versions are placed first since they run faster. that makes any errors reported during tests faster to report, which reduces wait time.

[dnalborczyk]

it appears to be a common usage pattern I have seen to use an ascending order, incl. in the GH actions docs. that said, I didn't know that there was a purpose behind the order in this repo, but I looked at some sample data and that statement is simply not [always consistently] true - or better, if anything, it's randomly true, e.g.: https://github.com/rollup/rollup/runs/2211099843 since each GH action pod I assume does not always get the same exact resources assigned.

anyhow, if needed, I can change it back to descending order.

[lukastaegert]

I guess it does not matter then, thanks for checking!