Stop listing black versions, not required for this repo

This repo has a pyproject.toml that specifies the python version
required, and due to that, specifying versions isn't required.

Author: consideRatio

pyproject.toml

@@ -142,14 +142,6 @@ remove-unused-variables = true
 # ref: https://black.readthedocs.io/en/stable/
 #
 [tool.black]
-# target-version should be all supported versions, see
-# https://github.com/psf/black/issues/751#issuecomment-473066811
-target_version = [
-    "py38",
-    "py39",
-    "py310",
-    "py311",
-]
 extend-exclude = 'contrib\/template\/'