Bump pre-commit hook versions

.pre-commit-config.yaml

@@ -17,11 +17,11 @@ repos:
     hooks:
       - id: isort
   - repo: https://gitlab.com/pycqa/flake8
-    rev: 3.9.2
+    rev: 4.0.1
     hooks:
       - id: flake8
   - repo: https://github.com/psf/black
-    rev: 21.7b0 # Replace by any tag/version: https://github.com/psf/black/tags
+    rev: 21.9b0 # Replace by any tag/version: https://github.com/psf/black/tags
     hooks:
       - id: black
   - repo: https://github.com/asottile/pyupgrade

requirements-dev.txt

@@ -1,8 +1,8 @@
 # Requirements. These can can be installed with:
 #   pip install -r requirements-dev.txt
 
-flake8~=3.9.2
-black~=21.7b0
+flake8~=4.0.1
+black~=21.9b0
 isort~=5.9.3
-pre-commit~=2.13.0
+pre-commit~=2.15.0
 cython==0.29.21