Update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/documentation.yaml

@@ -17,7 +17,7 @@ jobs:
       name: Setup TFLint
       with:
         tflint_version: v0.38.1
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: actions/setup-python@v4
     - uses: pre-commit/[email protected]
       # pre-commit fails if it changed files

.github/workflows/main.yml

@@ -9,7 +9,7 @@ jobs:
     name: Check if terraform files are formatted correctly.
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           ref: ${{ github.event.pull_request.head.ref }}