Add changelog note

Author: henrymercer

CHANGELOG.md

@@ -2,7 +2,8 @@
 
 ## [UNRELEASED]
 
-- Python automatic dependency installation will no longer fail for projects using Poetry that specify `virtualenvs.options.no-pip = true` in their `poetry.toml`. [#1431](https://github.com/github/codeql-action/pull/1431).
+- CodeQL Action v1 is now discontinued, and is no longer updated or supported. For better performance, improved security, and new features, upgrade to v2. For more information, see [this changelog post](https://github.blog/changelog/2022-04-27-code-scanning-deprecation-of-codeql-action-v1/). [#1467](https://github.com/github/codeql-action/pull/1466)
+- Python automatic dependency installation will no longer fail for projects using Poetry that specify `virtualenvs.options.no-pip = true` in their `poetry.toml`. [#1431](https://github.com/github/codeql-action/pull/1431)
 
 ## 2.1.38 - 12 Jan 2023
 
@@ -16,7 +17,7 @@
 
 - Update default CodeQL bundle version to 2.11.5. [#1412](https://github.com/github/codeql-action/pull/1412)
 - Add a step that tries to upload a SARIF file for the workflow run when that workflow run fails. This will help better surface failed code scanning workflow runs. [#1393](https://github.com/github/codeql-action/pull/1393)
-- Python automatic dependency installation will no longer consider dependecy code installed in venv as user-written, for projects using Poetry that specify `virtualenvs.in-project = true` in their `poetry.toml`. [#1419](https://github.com/github/codeql-action/pull/1419).
+- Python automatic dependency installation will no longer consider dependency code installed in venv as user-written, for projects using Poetry that specify `virtualenvs.in-project = true` in their `poetry.toml`. [#1419](https://github.com/github/codeql-action/pull/1419).
 
 ## 2.1.35 - 01 Dec 2022
 
@@ -317,7 +318,7 @@ No user facing changes.
 ## 1.0.4 - 28 Jun 2021
 
 - Fix `RUNNER_TEMP environment variable must be set` when using runner. [#594](https://github.com/github/codeql-action/pull/594)
-- Fix couting of lines of code for C# projects. [#586](https://github.com/github/codeql-action/pull/586)
+- Fix counting of lines of code for C# projects. [#586](https://github.com/github/codeql-action/pull/586)
 
 ## 1.0.3 - 23 Jun 2021