Symbol confusion after hasher panic in `intaglio` interners

Summary

Affected versions of this crate can leave all `SymbolTable` variants in an internally inconsistent state if a custom `BuildHasher` panics during `HashMap::insert` and the caller recovers with `catch_unwind`.

The `intern` implementations committed a `vec.push(...)` before the matching `map.insert(...)` completed. If hashing panicked in that window, later lookups and inserts could observe diverging `vec` and `map` lengths.

In release builds, this can lead to symbol confusion where a newly interned string resolves to previously interned attacker-controlled contents. In debug builds, the same corruption is detected by follow-up assertions and results in panics.

The flaw was corrected in version 1.13.3 by making the `vec` mutation transactional across unwind boundaries so partially inserted entries are rolled back before the panic propagates.