Target black at Python 3.10

Author: dmtucker

tox.ini

@@ -66,7 +66,7 @@ deps =
     mypy ~= 2.1.0
     pytest-xdist >= 3.6.0  # needed for type-checking
 commands =
-    black --check --target-version py38 src tests
+    black --check --target-version py310 src tests
     flake8 src tests
     mypy --strict src
     bandit --recursive src