Assert that scan returns nonzero exit in release smoke test

.github/workflows/integration_testing.yml

@@ -84,4 +84,4 @@ jobs:
           git clone https://github.com/pypa/pip pip
           cd pip
           secureli init --yes
-          secureli scan  --mode all-files --yes
+          [ ! secureli scan --mode all-files --yes ] # Expect/require non-zero exit code since scan should find issues