[Koha] Koha 3.22.21 release

[Julian Maurice]

The Koha community is proud to announce the release of Koha 3.22.21.

This is a maintenance release and contains several bugfixes.

The full release notes are available at
https://koha-community.org/koha-3-22-21-release/

Please note that Koha version 3.22 won't be maintained anymore and this
is the last 3.22 release. If you are still using it, you should consider
upgrading to a more recent version.