Fix scan-build reports and gate CI pipeline success on scan-build success
This is a follow-up from !563 (merged).
We need to squash all the
scan-build reports, then add the following to
.gitlab-ci.yml to gate pipeline success on there being no analysis reports:
variables: # Exit with a non-zero status if any bugs are found SCANBUILD: "scan-build --status-bugs"
This requires a Meson version bump to ≥ 0.49.0 to include the fix for https://github.com/mesonbuild/meson/issues/4334.