Bump pytest-cov from 5.0.0 to 6.0.0 (#16815)

(cherry picked from commit a54eb8b)

requirements-optional.txt

@@ -1,5 +1,5 @@
 # For running tests and checking code quality using these modules.
-pytest-cov==5.0.0
+pytest-cov==6.0.0
 redis==5.2.0
 pre-commit==4.0.1
 ruff==0.7.1