…PM repo on {archive/mirror}.mariadb.org

Exception: centos >= 9 which should be sorted out! (relative path on mirrors centos/$version/$platform)

Build_arch is used as $arch in bash_lib.sh, rpm_setup_mariadb_mirror{} to calculate mirror/archive URL.

{opensuse155-amd64,opensuse156-amd64} on https://mirror.mariadb.org/yum/$branch

Fixing minor upgrades in test_mode = 'ALL".
See: https://buildbot.dev.mariadb.org/#/builders/326/builds/14/steps/3/logs/stdio

…it as REQUIRED hence minor upgrades (all) will reflect the change during verifications.

> 10.5 MariaDB releases use liburing. Q3 release was linked against libaio which accounts for the differences found during testing.

- cache location is zypp
- "all" does not exist for clearing cache, instead zypper uses --all
-  when MariaDB.repo is first added the key should be trusted in a non-interactive manner, hence --gpg-auto-import-keys
- first zypper packages -r goes to /dev/null because there is a lot of noise from trusting the key. Sudo is needed to make the cache.
- second zypper packages -r runs as a normal user with no issues.