[Backport 16.4] Fix redis-namspace dependency version for UBI mailroom
What does this MR do?
Backport !1644 (merged) to 16-4-stable.
Fix redis-namspace dependency version for UBI mailroom
UBI-flavored gitlab-mailroom was using an older version of redis-namespace Gem which is incompatible with Ruby 3. The version is updated to match the Debian-flavored image.
Changelog: fixed
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Closes #1800 (closed)
Edited  by Clemens Beck