CHANGELOG: add entry for patch 1872

Author: dannywillems

CHANGELOG.md

@@ -25,6 +25,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - **Dependencies**: vendor redux-rs into `vendor/redux` to centralize all code
   in the monorepo ([#1814](https://github.com/o1-labs/mina-rust/pull/1814))
+- **Build System**: enforce GNU sed on macOS, require `brew install gnu-sed`
+  for `make fix-trailing-whitespace`, add CI test for cross-platform support,
+  fix [#1864](https://github.com/o1-labs/mina-rust/issues/1864)
+  ([#1872](https://github.com/o1-labs/mina-rust/pull/1872))
 - **Dependency**: use tag instead of references of o1-labs/proof-systems, fix
   [[#1674](https://github.com/o1-labs/mina-rust/issues/1674)]
   ([#1673](https://github.com/o1-labs/mina-rust/pull/1673))