Update actions/checkout action to v5

Author: renovate[bot]

.github/workflows/ci.yaml

@@ -30,7 +30,7 @@ jobs:
       PGPASSWORD: smartvm
       CC_TEST_REPORTER_ID: "${{ secrets.CC_TEST_REPORTER_ID }}"
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - name: Set up system
       run: bin/before_install
     - name: Set up Ruby