Update changelog to release version 3.5.0

Author: grongierisc

CHANGELOG.md

@@ -6,7 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
-## [unreleased] - Unreleased
+## [3.5.0] - 2025-06-30
 ### Added
 - Initial support for venv
 - New `send_generator_request` method in `iop` module to send generator requests