chore: add explicit "types" to tsconfig files

[trentm]

We use typescript v5 for compilation. However, sometimes external
tooling like an IDE will, by default, use the latest TS version for
editor support (like "squigglies" for lint/problems). This is the
case for VS Code and TS v6.

TS v6 changed the "types" tsconfig setting to default to [].
https://devblogs.microsoft.com/typescript/announcing-typescript-6-0/#types-now-defaults-to-[]
It previously defaulted to "enumerate everything in node_modules/@types".

As (mild) preparation for eventually migrating to TS v6 and
to be nice to developers whose IDE or other tool defaults to using TS
v6, let's explicitly list our "types".

I don't believe there is a downside to this, other than needing
to add "types" entries as usage changes.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.95%. Comparing base (4fdbfdd) to head (c403e6d).
⚠️ Report is 53 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6758      +/-   ##
==========================================
+ Coverage   94.78%   94.95%   +0.17%     
==========================================
  Files         374      377       +3     
  Lines       12439    12743     +304     
  Branches     2841     2896      +55     
==========================================
+ Hits        11790    12100     +310     
+ Misses        649      643       -6     

see 25 files with indirect coverage changes

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[trentm]

This is what I'm referring to:

---

sometimes external
tooling like an IDE will, by default, use the latest TS version

This is, of course, configurable -- at least in VS Code via the @command:typescript.selectTypeScriptVersion command.
A possible position here is to say: developers, configure your tools.
However, I find that pretty tedious. At least personally I have dozens of git clones of this and contrib repo that I work in regularly. I'd need to configure VS Code local settings in each.

Or we could add .vscode/settings.json to the repo... but I don't particularly want to go there.

[overbalance]

upgrade to 7 👹