A number of predefined actions have had major release, which warrant an update the workflow(s).
These updates don't actually contain any changed functionality, they are mostly just a change of the Node version used by the action itself (from Node 14 to Node 16).
Refs:
* https://github.com/actions/checkout/releases
* https://github.com/actions/upload-artifact/releases
Co-authored-by: jrfnl <jrfnl@users.noreply.github.com>
Closes GH-1442.