fix: remove checkout action from plan workflow

.gitea/workflows/terraform-plan.yml

@@ -16,8 +16,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
+      # NOTE: Gitea runners already provide the workspace checkout.
+      # Avoid actions/checkout to skip its post-job hook, which is causing
+      # false failures at the "Complete job" phase on this runner.
 
       - name: Create secrets.tfvars
         working-directory: terraform