update GitHub action for checkout

there was a new feature introduced to git, that prevents some of our
actions to run. The updated action handles this properly.

https://github.com/actions/checkout/issues/760

Signed-off-by: Martin Schurz <[email protected]>

.github/workflows/nginx_hardening.yml

@@ -34,7 +34,7 @@ jobs:
           # - fedora  # no support from geerlingguy role
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           path: ansible_collections/devsec/hardening
           submodules: true