chore(deps): update terraform-linters/setup-tflint action to v6

Author: renovate[bot]

.github/workflows/tflint.yml

@@ -23,7 +23,7 @@ jobs:
           path: ~/.tflint.d/plugins
           key: ${{ matrix.os }}-tflint-${{ hashFiles('.tflint.hcl') }}
 
-      - uses: terraform-linters/setup-tflint@v4
+      - uses: terraform-linters/setup-tflint@v6
         name: Setup TFLint
 
       - name: Show version