v0.42 on s390x: error: seccomp root emulation failed (is your architecture supported?)

Version 0.42 of ch-image fails at runtime on s390x even though it worked in the past (last tested older version: 0.38):

ch-run[2211]: error: seccomp root emulation failed (is your architecture supported?) (seccomp.c:265)
HEAD is now at b4bcfe8de8cc PULL almalinux:8
error: build failed: RUN command exited with 31

This was noticed by Debian's autopkgtest for Charliecloud. The corresponding test code is available on https://salsa.debian.org/hpc-team/charliecloud/-/blob/56561caba785fd599c13e8b9210033800f325859/debian/tests/tutorial.

The full autopkgtest logs for version 0.42 on s390x are available on https://ci.debian.net/packages/c/charliecloud/testing/s390x/65467225/. For reference: The corresponding logs for version 0.38 can be checked on https://ci.debian.net/packages/c/charliecloud/testing/s390x/65468782/.

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