dev env: add upper version constraint for isort to keep compatibility with python3.7 (has not reached end-of-life yet)

https://web.archive.org/web/20230203051620/https://github.com/PyCQA/isort/commit/47cedf3583f338e8ce9c906fc95c9fee6c57404d

https://github.com/fphammerle/python-manchester-code/commit/f174f7efcb41e22b7316211443752144e54205a0

Pipfile

@@ -15,6 +15,9 @@ pytest = "*"
 pytest-cov = "*"
 types-PyYAML = "*"
 
+# python3.7 compatibility
+# https://github.com/PyCQA/isort/commit/47cedf3583f338e8ce9c906fc95c9fee6c57404d
+isort = "<5.12"
 # python3.10 compatibility
 # >   File "[...]/lib/python3.10/site-packages/mypy/main.py", line 11, in <module>
 # >     from typing_extensions import Final, NoReturn

Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "b9040de07e04874a0f0a3eae442a7f22cddead44c401e40dbf5e0eecefe865a7"
+            "sha256": "ed983bc16a8adb6ac7b8e1c5c1c369a656cec07837fcb9bce591414b8d088bde"
         },
         "pipfile-spec": 6,
         "requires": {