Bump up checkout actions to try to fix CI

Author: kezhenxu94

.github/workflows/documentation.yaml

@@ -34,7 +34,7 @@ jobs:
             output-file: README.md
       fail-fast:  true
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: true
           ref: ${{ github.event.pull_request.head.ref }}