Davide Palozzi

## Bug Description it looks like the regex at https://github.com/nodejs/undici/blob/main/lib/fetch/util.js#L604 (`/((?sha256|sha384|sha512)-(?[A-z0-9+/]{1}.*={0,2}))( +[\x21-\x7e]?)?/i`) is incorrect in a few different ways. `A-z` will also match `[\]^_` which are invalid `base64` characters, and...