reprotest fails with "ModuleNotFoundError: No module named 'packaging'"?

https://salsa.debian.org/nabijaczleweli/archivemount/-/jobs/6154330#L555 says:

$ su salsa-ci -c "timeout ${SALSA_CI_BUILD_TIMEOUT_ARGS} reprotest \
  --min-cpus $(nproc --all) \
  --store-dir ${WORKING_DIR}/reprotest \
  --verbosity=2  \
  --vary=-time \
  --vary=user_group.available+=salsa-ci,domain_host.use_sudo=1 \
  ${SALSA_CI_DPKG_BUILDPACKAGE_ARGS:+--append-build-command=${SALSA_CI_DPKG_BUILDPACKAGE_ARGS}} \
  ${SALSA_CI_REPROTEST_ARGS} \
  ${WORKING_DIR}/*.dsc -- null" |& OUTPUT_FILENAME=reprotest.log filter-output
Traceback (most recent call last):
  File "/usr/bin/reprotest", line 33, in <module>
    sys.exit(load_entry_point('reprotest==0.7.27', 'console_scripts', 'reprotest')())
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/bin/reprotest", line 25, in importlib_load_entry_point
    return next(matches).load()
           ^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/importlib/metadata/__init__.py", line 205, in load
    module = import_module(match.group('module'))
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 995, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "/usr/lib/python3/dist-packages/reprotest/__init__.py", line 20, in <module>
    import pkg_resources
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 95, in <module>
    import packaging.specifiers
ModuleNotFoundError: No module named 'packaging'

And this doesn't feel like an issue that I have the ability to cause.