bump flake8 version in env and req-devs files

Author: MarcoGorelli

environment.yml

@@ -84,7 +84,7 @@ dependencies:
   # code checks
   - black=22.3.0
   - cpplint
-  - flake8=5.0.4
+  - flake8=6.0.0
   - flake8-bugbear=22.7.1 # used by flake8, find likely bugs
   - isort>=5.2.1  # check that imports are in the right order
   - mypy=0.990

requirements-dev.txt

@@ -63,7 +63,7 @@ flask
 asv
 black==22.3.0
 cpplint
-flake8==5.0.4
+flake8==6.0.0
 flake8-bugbear==22.7.1
 isort>=5.2.1
 mypy==0.990