Update CHANGELOG for PR #5061

Author: ponylang-main

CHANGELOG.md

@@ -8,6 +8,7 @@ All notable changes to the Pony compiler and standard library will be documented
 
 - Fix IOCP use-after-free crash ([PR #5055](https://github.com/ponylang/ponyc/pull/5055))
 - Fix pony-lint FileNaming false positives on Windows ([PR #5059](https://github.com/ponylang/ponyc/pull/5059))
+- Enforce documented maximum for --ponysuspendthreshold ([PR #5061](https://github.com/ponylang/ponyc/pull/5061))
 
 ### Added