Bump pytest-cov from 5.0.0 to 6.0.0 (#493)

requirements_testing.txt

@@ -2,7 +2,7 @@
 pre-commit==4.0.1
 pylint==3.3.1
 pytest==8.3.3
-pytest-cov==5.0.0
+pytest-cov==6.0.0
 pytest-icdiff==0.9
 ruff==0.7.1
 setuptools==75.3.0