Markdown is not converted to ROFF for man pages

[wilmerdooley]

Resolves #5095.

see https://manpages.debian.org/unstable/rust-coreutils/rust-test.1.en.html

[sylvestre]

please fix the failing jobs

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/date/resolution (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/date/date-locale-hour (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/symlink (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/tail-n0f (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/seq/seq-epipe is now passing!

[sylvestre]

please fix the jobs