Update CodeQL submodule to v2.22.1
Updates the CodeQL submodule.
To run the regular CI workflow for this pull request, either close and reopen it, or manually trigger the workflow from the "Actions" tab.
For future reference: I have manually disabled this workflow now. The problem is that there were (already a few years ago when this PR was first opened) multiple deprecations or breaking changes in the CodeQL Java library API. And at least back then you had to compile all queries to find the warnings in errors; the VS Code extension only showed issues for open files (and the files they referred to). But CodeQL compilation was (and maybe still is) slow which makes it not very pleasant to compile the hundreds of files within this repository. Maybe performance could be improved if this repository used CodeQL workspaces and CodeQL packs, see #26.