Update changelog for progress reporting on post-evaluation steps

Author: nickrolfe

extensions/ql-vscode/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [UNRELEASED]
 
+- Update the progress window with details on potentially long-running post-processing steps after running a query. [#3622](https://github.com/github/vscode-codeql/pull/3622)
+
 ## 1.13.0 - 1 May 2024
 
 - Add Ruby support to the CodeQL Model Editor. [#3584](https://github.com/github/vscode-codeql/pull/3584)