* Add ArchLinux, Debian Bullseye and CentOS Stream 8 to CI.
* Add Alpine to CI matrix as well.
(cherry picked from commit a06903f33a)
Co-authored-by: Felix Fontein <felix@fontein.de>
* Add Ubuntu 20.04 to CI.
* Skip mqtt test on Ubuntu 20.04.
* Use explicit disable instead of aliases.
* Add Ubuntu 20.04 specific config for setup_postgresql_db.
* Fix postgres version.