drop support for Node 14 (EOL)

[cvan]

from GitHub's Changelog blog:

Node 12 has been out of support since April 2022, as a result we have started the deprecation process of Node 12 for GitHub Actions. We plan to migrate all actions to run on Node16 by Summer 2023.

Following on from our warning in workflows using Node 12, we will start enforcing the use of Node16 rather than Node12 on the 18th of May.

What you need to do

• For Actions maintainers: Update your actions to run on Node 16 instead of Node 12 (Actions configuration settings)
• For Actions users: Update your workflows with latest versions of the actions which runs on Node 16 (Using versions for Actions)