Evaluate supported Node versions

[GeorgeCadwallader]

Problem to solve

We currently have a test matrix for Node versions 14, 16, and 18. This was set up quite a while ago so it would make sense to take a look at these and potentially change the versions we are testing for.

Proposal

Based off of the official Node.js release schedule we should make the following changes to our Node.js test coverage:

• It seems like as I write this (11th April 2023) version 14.x is going "end-of-life" at the end of the month (30th April 2023). So we should probably look at removing testing for this version, and also declaring on the repo that we are no longer actively supporting this version of Node.
• Even though 18 is the current LTS maybe we should look at adding 20 into our actively supported versions. Since it will at some point become the new LTS. Something to look into, depending on how much work this would be initially.

Links / References

• Node.js release schedule