chore: update changelog

Author: ErdaradunGaztea

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to Shiny for Python will be documented in this file.
 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]
+
+### Changes
+
+* `selectize`, `remove_button`, and `options` parameters of `ui.input_select()` have been deprecated; use `ui.input_selectize()` instead. (#1947) 
+
 ## [1.4.0] - 2025-04-08
 
 ## New features