Update rust edition

Signed-off-by: Yang Zhang <yang.zhang@pingcap.com>

Author: v01dstar

Cargo.toml

@@ -2,7 +2,7 @@
 name = "raft-engine"
 version = "0.4.2"
 authors = ["The TiKV Project Developers"]
-edition = "2018"
+edition = "2024"
 rust-version = "1.85.0"
 description = "A persistent storage engine for Multi-Raft logs"
 readme = "README.md"