chore: bump version to 4.0.0

Author: wboayue

Cargo.toml

@@ -4,7 +4,7 @@ default-members = ["."]
 
 [package]
 name = "ibapi"
-version = "3.3.0"
+version = "4.0.0"
 edition = "2021"
 authors = ["Wil Boayue <wil@wsbsolutions.com>"]
 description = "A Rust implementation of the Interactive Brokers TWS API, providing a reliable and user friendly interface for TWS and IB Gateway. Designed with a focus on simplicity and performance."