Update changelog

Author: aeisenberg

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [UNRELEASED]
 
 - You can now configure CodeQL within your code scanning workflow by passing a `config` input to the `init` Action. See [Using a custom configuration file](https://aka.ms/code-scanning-docs/config-file) for more information about configuring code scanning. [#1590](https://github.com/github/codeql-action/pull/1590)
+- Updated the SARIF JSON schema file to the latest from [oasis-tcs/sarif-spec](https://github.com/oasis-tcs/sarif-spec/blob/123e95847b13fbdd4cbe2120fa5e33355d4a042b/Schemata/sarif-schema-2.1.0.json). [#1668](https://github.com/github/codeql-action/pull/1668)
 
 ## 2.3.2 - 27 Apr 2023