GHSA-C2HM-MJXV-89R4 Multiple soundness issues in lexical

lexical contains multiple soundness issues: 1. Bytes::read allows creating instances of types with invalid bit patterns 1. BytesIter::read advances iterators out of bounds 1. The BytesIter trait has safety invariants but is public and not marked unsafe 1. writefloat calls MaybeUninit::assumeinit ...