v3 => v4

Author: mbg

README.md

@@ -82,7 +82,7 @@ See the full list of GHES release and deprecation dates at [GitHub Enterprise Se
 
 ## Keeping the CodeQL Action up to date
 
-We recommend referencing the CodeQL Action using a major version tag (e.g. `v3`) in your workflow file. This ensures your workflow automatically picks up the latest release within that major version, including bug fixes, new features, and updated CodeQL CLI versions.
+We recommend referencing the CodeQL Action using a major version tag (e.g. `v4`) in your workflow file. This ensures your workflow automatically picks up the latest release within that major version, including bug fixes, new features, and updated CodeQL CLI versions.
 
 If you pin to a specific commit SHA or patch version tag, ensure you keep it updated (e.g. via [Dependabot](https://docs.github.com/en/code-security/dependabot/working-with-dependabot/keeping-your-actions-up-to-date-with-dependabot)). Some CodeQL Action features are controlled by server-side flags that may be removed over time, which can cause pinned versions to lose functionality.