pre-commit: Update isort version to 5.12.0 (#877)

poetry version 1.5.0 broke installs of isort prior to 5.11.5 (see PyCQA/isort#2077 and PyCQA/isort#2078), so we need to upgrade.

Authors:
  - Lawrence Mitchell (https://github.com/wence-)

Approvers:
  - H. Thomson Comer (https://github.com/thomcom)
  - Mark Harris (https://github.com/harrism)

URL: #877

.pre-commit-config.yaml

@@ -2,7 +2,7 @@
 
 repos:
       - repo: https://github.com/PyCQA/isort
-        rev: 5.10.1
+        rev: 5.12.0
         hooks:
               - id: isort
                 # Use the config file specific to each subproject so that each