Bump version to v1.9.4 (#3023)

Co-authored-by: github-actions[bot] <github-actions@github.com>

Author: github-actions[bot]

extensions/ql-vscode/CHANGELOG.md

@@ -1,5 +1,7 @@
 # CodeQL for Visual Studio Code: Changelog
 
+## [UNRELEASED]
+
 ## 1.9.3 - 26 October 2023
 
 - Sorted result set filenames now include a hash of the result set name instead of the full name. [#2955](https://github.com/github/vscode-codeql/pull/2955)

extensions/ql-vscode/package-lock.json

@@ -4,7 +4,7 @@
   "description": "CodeQL for Visual Studio Code",
   "author": "GitHub",
   "private": true,
-  "version": "1.9.3",
+  "version": "1.9.4",
   "publisher": "GitHub",
   "license": "MIT",
   "icon": "media/VS-marketplace-CodeQL-icon.png",