Bump version to v1.4.9

Author: shati-patel

extensions/ql-vscode/CHANGELOG.md

@@ -1,5 +1,7 @@
 # CodeQL for Visual Studio Code: Changelog
 
+## [UNRELEASED]
+
 ## 1.4.8 - 05 May 2021
 
 - Copy version information to the clipboard when a user clicks the CodeQL section of the status bar. [#845](https://github.com/github/vscode-codeql/pull/845)

extensions/ql-vscode/package-lock.json

@@ -4,7 +4,7 @@
   "description": "CodeQL for Visual Studio Code",
   "author": "GitHub",
   "private": true,
-  "version": "1.4.8",
+  "version": "1.4.9",
   "publisher": "GitHub",
   "license": "MIT",
   "icon": "media/VS-marketplace-CodeQL-icon.png",