Update CHANGELOG for version 1.2.43 (#1602)

Author: Kriskras99

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.2.43](https://github.com/rust-lang/cc-rs/compare/cc-v1.2.42...cc-v1.2.43) - 2025-10-24
+
+### Other
+
+- Mark `static_flag` and `shared_flag` as deprecated ([#1582](https://github.com/rust-lang/cc-rs/pull/1582))
+
 ## [1.2.42](https://github.com/rust-lang/cc-rs/compare/cc-v1.2.41...cc-v1.2.42) - 2025-10-24
 
 ### Other