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

@@ -4,7 +4,7 @@ verify_ssl = true
 name = "pypi"
 
 [packages]
-ical2vdir = {editable = true,path = "."}
+ical2vdir = {editable = true, path = "."}
 
 [dev-packages]
 black = "*"
@@ -16,6 +16,9 @@ pylint-import-requirements = "*"
 pytest = "*"
 pytest-cov = "*"
 
+# 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": "544b126e4fcff910d8ca2a86e907e6d082151b304069effe5acbf91b1dc71d10"
+            "sha256": "c2df4ab1bb691c23a5bb3e763195b1d60c3a041f2145e978b0be1513e21c8475"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -313,11 +313,11 @@
         },
         "isort": {
             "hashes": [
-                "sha256:6db30c5ded9815d813932c04c2f85a360bcdd35fed496f4d8f35495ef0a261b6",
-                "sha256:c033fd0edb91000a7f09527fe5c75321878f98322a77ddcc81adbd83724afb7b"
+                "sha256:6be1f76a507cb2ecf16c7cf14a37e41609ca082330be4e3436a18ef74add55db",
+                "sha256:ba1d72fb2595a01c7895a5128f9585a5cc4b6d395f1c8d514989b9a7eb2a8746"
             ],
-            "markers": "python_version >= '3.7'",
-            "version": "==5.11.4"
+            "index": "pypi",
+            "version": "==5.11.5"
         },
         "lazy-object-proxy": {
             "hashes": [