fix: correct checkout configuration in terraform-checks workflow

- Use conditional ref for pull_request vs push events
- Remove repository parameter that breaks with forks
- Add proper GITHUB_TOKEN for authentication
- Fixes checkout failures for fork-based PRs

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: vjdhama

.github/workflows/terraform-checks.yaml

@@ -98,8 +98,8 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.ref }}
-          repository: ${{github.event.pull_request.head.repo.full_name}}
+          ref: ${{ github.event_name == 'pull_request' && github.head_ref || github.ref }}
+          token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Terraform min/max versions
         id: minMax