Remove Python 3.7 and 3.8 remains.

Author: efkon-tkem

setup.cfg

@@ -27,7 +27,7 @@ classifiers =
 package_dir =
     = src
 packages = find:
-python_requires = >= 3.7
+python_requires = >= 3.9
 
 [options.packages.find]
 where = src

tox.ini

@@ -10,8 +10,7 @@ commands =
 
 [testenv:check-manifest]
 deps =
-    check-manifest==0.44; python_version < "3.8"
-    check-manifest; python_version >= "3.8"
+    check-manifest
 commands =
     check-manifest
 skip_install = true
@@ -31,8 +30,7 @@ commands =
 [testenv:flake8]
 deps =
     flake8
-    flake8-black; implementation_name == "cpython"
-    black==22.12.0; implementation_name == "cpython" and python_version < "3.8"
+    flake8-black
     flake8-bugbear
     flake8-import-order
 commands =