CI specs: Never use ! ... as a check (followup)

This is a followup of 6015300d34

This particular instance was not discovered before due to the macro.

tests/python-setuptools_scm.spec

@@ -62,7 +62,7 @@ Summary:        %{summary}
 
 # Internal check for our macros: Assert both toxenvs were executed.
 grep -E 'py%{python3_version_nodots}-test: (OK|commands succeeded)' toxlog
-%{?!with_flake8:! }grep -E 'flake8: (OK|commands succeeded)' toxlog
+grep -E 'flake8: (OK|commands succeeded)' toxlog %{?!with_flake8:&& exit 1 || true}
 
 # Internal check for our macros
 # making sure that %%{_pyproject_ghost_distinfo} has the right content