CI: Added cfengine format --check to GH Action

Ticket: ENT-14151
Signed-off-by: Ole Herman Schumacher Elgesem <ole@northern.tech>

Author: olehermanse

.github/workflows/ci.yml

@@ -32,3 +32,5 @@ jobs:
       run: pytest promise-types/ -v
     - name: Lint policy with CFEngine CLI
       run: cfengine lint --strict no ./
+    - name: Check formatting with CFEngine CLI
+      run: cfengine format --check