GHSA-f67m-9j94-qv9j: Parser creates invalid uninitialized value

The vulnerability stems from using mem::uninitialized() with httparse::Header in HTTP1 parsing logic. The pull request #2545 specifically shows changes in role.rs where Server::parse and Client::parse methods were modified to replace mem::uninitialized() with MaybeUninit. These functions handle header parsing and were directly mentioned in commit messages ('Server::parse - use MaybeUninit' and 'Client::parse - use MaybeUninit'). The HTTP1 parser is explicitly called out in the advisory as the affected component, and httparse::Header's reference-containing nature makes uninitialized memory particularly dangerous here.