attest: replace references to Node's builtin assertions

[ssalbdivad]

attest currently relies on Node's builtin deepStrictEqual for its default .equals comparison, but this feels like a big problem:

import { type } from "arktype";
import assert from "node:assert/strict";

// Currently crashes with OOM exception
assert.deepStrictEqual(type.string, type.boolean);

I'd like to find either a simple string diffing implementation we could use internally based on generate .snap contents or some targeted external solution for this without these issues (and potentially also clearer diffs).

In the meantime I will try to avoid this specific case happening by ensuring we only compare functions based on reference equality or similar.

[PointSingularity]

Here are some potential options:

• superdiff
• microdiff
• jsondiffpatch