Comment 17 for bug 2003669

I think "libopencryptoki0_3.20.0+dfsg-0ubuntu2_s390x.deb" was only the PPA version.
The regular archive versions may have slightly different version, and I think that is the case here:
rmadison says that the latest version in lunar/23.04 is "3.20.0+dfsg-0ubuntu1.1":
$ rmadison --arch=s390x opencryptoki | grep lunar
 opencryptoki | 3.20.0+dfsg-0ubuntu1 | lunar/universe | s390x
 opencryptoki | 3.20.0+dfsg-0ubuntu1.1 | lunar-updates/universe | s390x
And the corresponding changelog (https://launchpad.net/ubuntu/+source/opencryptoki/+changelog) says:
"
opencryptoki (3.20.0+dfsg-0ubuntu1.1) lunar; urgency=medium

  * Add d/p/lp-2022088-fix-p11sak-failure-to-find-libopencryptoki.so.patch
    to fix the failure that p11sak is not able to find libopencryptoki as
    plugin, by adjusting 'default_pkcs11lib'. (LP: #2022088)
  * d/opencryptoki.install: install full set of etc/opencryptoki build
    folder to esp. catch all generated conf files and on top make the arch-
    specific file 'opencryptoki.install.s390x' obsolete. (LP: #2018911)
  * d/opencryptoki.postinst: change strength.conf file permissions to 640
    which is checked/forced by the opencryptoki code. (LP: #2018908)
"
So the bug LP#2003669 is fixed in "3.20.0+dfsg-0ubuntu1.1".

Means if you have a 23.04 system,
just update the package index:
sudo apt update
and update the entire system to the latest level (sudo apt full-upgrade) or selectively only the opencryptoki package(s) (sudo apt install libopencryptoki0).

Btw. the following will give you (after apt update) a picture about whats available to install and what is currently installed):
apt-cache policy opencryptoki libopencryptoki0 libopencryptoki-dev