Update rpm2docserv to version 20221129.a10bb7c / rev 12 via SR 1039537
https://build.opensuse.org/request/show/1039537
by user kukuk + dimstar_suse
- Update vendor dir
- Require /usr/bin/mandoc: we rely on mandoc to render the man
pages as html.
- Fix building on Leap 15.4