`z.core.File` is incompatible with `globalThis.File` type

[ahrjarrett]

It looks like z.core.File changes added in v4.0.6 are not compatible with globalThis.File.

Looks like it's because the size and type properties in z.core.File are mutable, but are readonly in globalThis.File.

Repro

import { expectTypeOf, test } from 'vitest'
import * as z from 'zod'

test('repro', () => {
  const file = new File([], 'test.txt')
  expectTypeOf(z.file().parse(file)).toEqualTypeOf(file)
  //                                               𐙘__𐙘 not equal because `size` and `type` are mutable
})

Should be a quick fix, will open a PR in a few