* added/updated to Python 3.11 in CI
* specify `check-latest: true` for `actions/setup-python` so we always use the latest version
* scriptcheck.yml: added note about `shellcheck`
* cleaned up triage.pro and pass all triage files to selfcheck
* CI-unixish.yml: factored out redundant selfcheck flags
* CI-unixish.yml: cleaned up selfcheck suppressions and fixed warnings
* added explicit `missingInclude` checks to selfcheck to work around current issues/limitations / fixed selfcheck includes / added some unit tests for `missingInclude`
* applied the selfcheck changes to the sanitizer jobs
* only fail TSAN CI build in case of TSAN error / updated sanitizer CI build TODOs