Upgrade black / fix CI

The CI now fails:

+ 1648720957.432871	 black --check $SRC_DIR/src/micado
Traceback (most recent call last):
  File "$PREFIX/bin/black", line 10, in <module>
    sys.exit(patched_main())
  File "$PREFIX/lib/python3.10/site-packages/black/__init__.py", line 1367, in patched_main
    patch_click()
  File "$PREFIX/lib/python3.10/site-packages/black/__init__.py", line 1353, in patch_click
    from click import _unicodefun
ImportError: cannot import name '_unicodefun' from 'click' ($PREFIX/lib/python3.10/site-packages/click/__init__.py)

This is because black < 22.3.0 does not work with click 8.1.0: https://stackoverflow.com/questions/71673404/importerror-cannot-import-name-unicodefun-from-click

Best would be to just upgrade to black 22.3.0, because that is planned anyway. However, that would reformat some files. And would require another docker image.

Simpler would be to pin click < 8.1.0 or so.