Upgrade githubactions to CodeQL v4

[DevSkim](https://github.com/twogood/Activout.RestClient/actions/runs/22441040757/job/64983208505#step:5:9)
CodeQL Action v3 will be deprecated in December 2026. Please update all occurrences of the CodeQL Action in your workflow files to v4. For more information, see https://github.blog/changelog/2025-10-28-upcoming-deprecation-of-codeql-action-v3/
