CI is broken, probably because of a dependency

[MatthijsBurgh]

The CI is broken, probably because of an update of a dependency.

For your convenience, I checked the installed dependency versions on the last working Ubuntu 3.8 run compared with the recent failing one. See the diff below.

--- <unnamed>
+++ <unnamed>
@@ -1,24 +1,24 @@
-astroid-2.9.0
-attrs-21.2.0
+astroid-2.9.3
+attrs-21.4.0
 black-21.12b0
 click-8.0.3
 darker-1.3.3.dev0
-filelock-3.4.0
+filelock-3.4.2
 flake8-3.9.2
 iniconfig-1.1.1
 isort-5.10.1
-lazy-object-proxy-1.6.0
+lazy-object-proxy-1.7.1
 mccabe-0.6.1
-mypy-0.910
+mypy-0.931
 mypy-extensions-0.4.3
 packaging-21.3
 pathspec-0.9.0
-platformdirs-2.4.0
+platformdirs-2.4.1
 pluggy-1.0.0
 py-1.11.0
 pycodestyle-2.7.0
 pyflakes-2.3.1
-pygments-2.10.0
+pygments-2.11.2
 pylint-2.12.2
 pyparsing-3.0.6
 pytest-6.2.5
@@ -29,7 +29,7 @@
 pytest-mypy-0.8.1
 regex-2021.11.10
 toml-0.10.2
-tomli-1.2.2
-types-toml-0.10.1
+tomli-1.2.3
+types-toml-0.10.3
 typing-extensions-4.0.1
 wrapt-1.13.3

[MatthijsBurgh]

Will be fixed by #258