Revert "Update pre-commit environments (#467)"

Virtualenv is currently broken and upstream packages are at war over whose
responsibility it is to not break users see e.g.

pre-commit/pre-commit#2178

This reverts commit 8e114e8.

.pre-commit-config.yaml

@@ -2,13 +2,13 @@ repos:
 
 # Automatically sort imports
 - repo: https://github.com/PyCQA/isort.git
-  rev: 5.10.1
+  rev: 5.9.2
   hooks:
   - id: isort
 
 # Automatic source code formatting
 - repo: https://github.com/psf/black
-  rev: 21.12b0
+  rev: 21.6b0
   hooks:
   - id: black
     args: [--safe, --quiet]
@@ -17,14 +17,13 @@ repos:
 
 # Linting
 - repo: https://github.com/PyCQA/flake8
-  rev: 4.0.1
+  rev: 3.9.2
   hooks:
   - id: flake8
-    additional_dependencies: ['flake8-comprehensions==3.8.0']
 
 # Syntax validation and some basic sanity checks
 - repo: https://github.com/pre-commit/pre-commit-hooks
-  rev: v4.1.0
+  rev: v4.0.1
   hooks:
   - id: check-ast
   - id: check-yaml