We're skipping two major typescript-eslint versions, so there are a
bunch of changes here, including:
- it's catching a lot of things it didn't catch in the past, for
reasons unclear to me
- no-unused-vars has to be explicitly disabled in global-types now
- a lot of `ts-ignore`s were never necessary and have been fixed
- Crashlogger can now handle being thrown things that aren't errors.
This has never been a problem in the past, but to satisfy TypeScript
we might as well not die in a fire on the off chance someone tries to
`throw null` or something.
