Vitest's inference isn't as good, unfortunately.

Tests now fail if they don't explicitly test anything.

`fakes.ts` no longer exists and `types.ts` is fully tested (somehow).

Drop `filterMap` in favor of the `flatMap` method.
Prefer the `includes` method.
Replace sole source of mutability with a ternary.

We only write nice, pure functions that don't use classy state.
If we let ts know, it'll stop complaining sometimes.
We've already done it elsewhere, this just makes it consistent.

Glob provides a root option, which we should use instead of `join`.
Why? `join` will normalize it to a Windows path.
node-glob only takes POSIX paths, so we can't use `join`.

Fixes jeffijoe#131.

This is explicitly warned against in the Node documentation,
to the point that Deno doesn't even support doing this (easily).
This is also a potential bug Windows bug as well.
And best part of all: the new code is shorter!

And squeeze out some optimizations in globbing.
We can glob for all of the patterns at once,
and also ignore the ignored workspaces to reduce i/o.

It doesn't seem to be installed anymore?

Can bump with Node 18.