feat!: switch to ESM and update dependencies

[JoshuaKGoldberg]

Draft PR just testing things out - not intended or ready for review yet.

Purpose of this pull request?

• Documentation update
• Bug fix
• Enhancement
• Other, please explain: internal overhaul that switches from CJS to ESM

What changes did you make?

1. Added "type": "module" to package.json
2. Ran ncu -u to update all dependencies to latest
3. Bumps Node versions in CI to be >=18 - the LTS majors for the next 5 weeks

No actual functionality or logic should be changed.

Is there anything you'd like reviewers to focus on?

I normally go for smaller, slower rollouts. But since doctor is technically a standalone tool separate from yo/Yeoman I thought this'd be a good way to test for breakages from ESM or new package dependencies. I wouldn't be upset if told to reduce scope, though.

[socket-security]

New, updated, and removed dependencies detected. Learn more about Socket for GitHub ↗︎

Package	New capabilities	Transitives	Size	Publisher
npm/ansi-styles@3.2.1 ➜ 6.2.1	None	0	17.5 kB	sindresorhus
npm/bin-version-check@4.0.0 ➜ 6.0.0	None	+1	7.66 kB	sindresorhus
npm/chalk@2.4.2 ➜ 5.4.1	None	0	44.2 kB	sindresorhus
npm/global-agent@2.2.0 ➜ 3.0.0	None	+19	520 kB	gajus
npm/latest-version@3.1.0 ➜ 9.0.0	Transitive: environment, filesystem	+8	135 kB	sindresorhus
npm/log-symbols@2.2.0 ➜ 7.0.0	None	0	4.4 kB	sindresorhus
npm/mocha@4.1.0 ➜ 11.2.0	None	+26	4.55 MB	joshuakgoldberg, uzlopak, voxpelli
npm/proxyquire@1.8.0 ➜ 2.1.3	Transitive: environment, filesystem	+10	330 kB	bendrucker
npm/sinon@4.5.0 ➜ 19.0.4	Transitive: environment, eval	+12	2.46 MB
npm/xo@0.24.0 ➜ 0.60.0	Transitive: environment, eval, filesystem, shell, unsafe	+307	22.4 MB	sindresorhus

View full report↗︎