Update actions/checkout action to v4 (#8)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/update.yml

@@ -11,7 +11,7 @@ jobs:
       pull-requests: write # For actions/github-script
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
 
       - name: Get npm cache directory path
         id: npm-cache-dir-path