Update dependency flake8 to v7.3.0

Author: renovate[bot]

requirements.txt

@@ -4,7 +4,7 @@ autopep8==2.3.2
 coverage==7.9.1
 dill==0.4.0
 exceptiongroup==1.3.0
-flake8==7.2.0
+flake8==7.3.0
 iniconfig==2.1.0
 isort==6.0.1
 lazy-object-proxy==1.11.0