feat: enable Ajv2019 and Ajv2020

[jmjf]

Closes #151 and probably makes #105 moot.

The for...of approach to tests seemed simple. If maintainers don't like it, I'm open to input on what you'd prefer.

• [x] run npm run test ~and npm run benchmark~ (there is no benchmark script)
• [x] tests and/or benchmarks are included
• [x] documentation is changed or added
• [x] commit message and code follows the Developer's Certification of Origin and the Code of conduct

Checklist

• [x] run npm run test and npm run benchmark
• [x] tests and/or benchmarks are included
• [x] documentation is changed or added
• [x] commit message and code follows the Developer's Certification of Origin and the Code of conduct

[jmjf]

Lint is failing in CI. When I ran lint locally on main, it failed with the same error. I'm not sure what the lint issue is.

[jmjf]

lint seems failing

Lint fails in main (see also this comment) with the same errors. At the time I created this PR, I saw several merged PRs that had the same lint failures.

If the team wants to recommend lint config changes the team considers acceptable, I'm willing to make them. (I use biome, not eslint, so am not familiar with eslint config.)

> @fastify/[email protected] lint
> eslint


/home/jmjf/dev/ajv-compiler/types/index.d.ts
  12:18  error  'buildCompilerFromPool' is defined but only used as a type    @typescript-eslint/no-unused-vars
  15:18  error  'buildSerializerFromPool' is defined but only used as a type  @typescript-eslint/no-unused-vars

✖ 2 problems (2 errors, 0 warnings)