Revert "kernel_hardening: Use Lynis from the playbook itself"

This reverts commit b4bebc8.

The sysctl handler is run only after the Lynis tests (in the playbook),
so we'll run Lynis from the Actions instead.

.github/workflows/ansible-playbook.yml

@@ -173,7 +173,9 @@ jobs:
       - name: Run Lynis (pre-harden)
         run: sudo lynis audit system --skip-plugins --tests-from-group kernel_hardening
       - name: Run Ansible playbook for kernel
-        run: ansible-playbook harden.yml --tags kernel --extra-vars run_lynis_after_hardening=true
+        run: ansible-playbook harden.yml --tags kernel
+      - name: Run Lynis
+        run: sudo lynis audit system --skip-plugins --tests-from-group kernel_hardening
       - name: chmod Lynis log
         run: sudo chmod -c 644 /var/log/lynis.log
       - name: Archive Lynis log