CHANGELOG: add description for patch 1548

Author: dannywillems

CHANGELOG.md

@@ -96,6 +96,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#1539](https://github.com/o1-labs/mina-rust/pull/1539))
 - **Ledger**: document, clean and add tests for the crate `mina-tree`
   ([#1531](https://github.com/o1-labs/mina-rust/pull/1531).
+- **CI**: build benches for each PR with the workflow `tests`, and fix the step
+  in the workflow `build` by adding the missing SQLx/SQLite setup
+  ([#1548](https://github.com/o1-labs/mina-rust/pull/1548))
 
 ## v0.17.0