Currently LGTM.com is used, but they will stop operating at the end of the year, https://github.blog/2022-08-15-the-next-step-for-lgtm-com-github-code-scanning/. There has been an attempt to use CodeQL #22446 but a bit more working is needed.

pylint/flake8 sorts out some of the issues though for the Python code.

Related: #17063

Should we try to get CodeQL up and running? Any other code checking tool/site worth considering?