Broken builds on Ubuntu 20.04

[stweil]

make all succeeds, but make check fails for any Python version:

[...]
&&  { /home/runner/work/ocrd_all/ocrd_all/venv/sub-venv/headless-tf1/bin/cor-asv-ann-repl --help >/dev/null 2>&1 || /home/runner/work/ocrd_all/ocrd_all/venv/sub-venv/headless-tf1/bin/cor-asv-ann-repl -h >/dev/null; }
. /home/runner/work/ocrd_all/ocrd_all/venv/sub-venv/headless-tf1/bin/activate && pip check
scikit-image 0.21.0 has requirement imageio>=2.27, but you have imageio 2.14.1.
scikit-image 0.21.0 has requirement tifffile>=2022.8.12, but you have tifffile 2021.11.2.
make[1]: *** [Makefile:737: check] Error 1
[...]

[stweil]

See results from a complete test matrix:

• Ubuntu 20.04 fails with with the error above.
• Ubuntu 22.04 works fine.
• Ubuntu 24.04 fails because it requires an update for ocrd_tesserocr.

[bertsky]

So there's a new scikit-image, the dependencies of which are in conflict with some of ours.

Who is it that wants (and holds) imageio and tifffile here?

[stweil]

cor-asv-ann?