maint(precommit): Apply isort (#3195)

* Apply isort

* Tweak isort config

* Add env.py as a known_first_party

* Add one missing known first party

* Make config compat with older isort versions

* Add another comment

* Revert pyproject setting

docs/conf.py

@@ -13,12 +13,12 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys
 import os
+import re
 import shlex
 import subprocess
+import sys
 from pathlib import Path
-import re
 
 DIR = Path(__file__).parent.resolve()