upgrade dependencies

session/handler.go: only convert server-sent tracker packets to lates…

…t if `SyncProtocol` is enabled

upgrade dependencies

transport: dropped TCP & RakNet support and improved error handling

upgrade dependencies

transport: added Spectral support

protocol/writer.go: combine packet length and data into a single writ…

…e operation

server/conn.go: add support for server-side multi-version

session/handler.go: add multi-version support for decoding client pac…

…kets

upgrade dependencies