CHANGELOG: add entry for OCaml node update automation script

Author: dannywillems

CHANGELOG.md

@@ -20,6 +20,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - **Documentation**: Add instructions to update the OCaml node dependencies.
   ([#1237](https://github.com/o1-labs/openmina/pull/1237))
+- **Development Tools**: Automation script for updating OCaml node references
+  with comprehensive documentation and CI testing to ensure reproducibility
+  ([#1252](https://github.com/o1-labs/openmina/pull/1252))
 - **Documentation**: Complete Docusaurus-based documentation website with
   comprehensive guides for node runners, developers, and researchers
   ([#1234](https://github.com/o1-labs/openmina/pull/1234)). It migrates all the