Add changelog note

Author: henrymercer

CHANGELOG.md

@@ -6,7 +6,7 @@ Note that the only difference between `v2` and `v3` of the CodeQL Action is the
 
 ## [UNRELEASED]
 
-No user facing changes.
+- Fix an issue where the CodeQL Action would fail to load a configuration specified by the `config` input to the `init` Action. [#2147](https://github.com/github/codeql-action/pull/2147)
 
 ## 3.24.2 - 15 Feb 2024