serde_ipld_dagcbor has a limit of 256 and serde_json of 128. This PR removes the depth checking so we fall back on the libraries' behaviors instead, which means a tiny bit less code and stuff to maintain. Många bäckar små. But more importantly, this makes us a bit more tolerant to weird records.
Not a big deal, but it was low effort. Also branches off of the record blobs PR, will rebase when it's merged.