Update changelog and version after v1.1.1

Author: github-actions[bot]

CHANGELOG.md

@@ -1,5 +1,9 @@
 # CodeQL Action and CodeQL Runner Changelog
 
+## [UNRELEASED]
+
+No user facing changes.
+
 ## 1.1.1 - 17 Feb 2022
 
 - The CodeQL CLI versions up to and including version 2.4.4 are not compatible with the CodeQL Action 1.1.1 and later. The Action will emit an error if it detects that it is being used by an incompatible version of the CLI. [#931](https://github.com/github/codeql-action/pull/931)