Merge branch 'ps/check-docs-fix'

"make check-docs" noticed problems and reported to its output but failed to signal its findings with its exit status, which has been corrected. * ps/check-docs-fix: ci/test-documentation: work around SyntaxWarning in Python 3.12 gitlab-ci: add job to run `make check-docs` Documentation/lint-manpages: bubble up errors Makefile: extract script to lint missing/extraneous manpages