Update to Node 20

[slifty]

From the recent graphile-worker dependabot PR:

As of 24th October 2023, Node 20 is the active LTS and Node 18 is maintainence LTS

Is there a reason we should avoid updating?

[slifty]

Realizing this might be easier to do after completing #622 -- I may wait to take it on until then.

[jasonaowen]

Yeah, I think the only reason to avoid/defer uploading is because of the associated infra work - it should be easier as a DO App!

[bickelj]

Does DO separate the node version from the codebase? Of course that would be easier but with its own costs.

[bickelj]

(See #833 discussion)

I just tried running npm ci and npm run build using node 18, then did npm run migrate and npm run start and all seemed OK. I'll update node to 20 in the deploy repo (runtime) and then @slifty volunteered to update it here in the service repo (build time).

So I got mixed up (been a while) it's all defined here in the service repo. I'll take a first pass at updating.

[bickelj]

@slifty OK, first pass is in PR #837 but I may have missed some spots or it may fail, I hereby leave that branch to thee!

[slifty]

This is complete 🎉