ci: update to actions/checkout@v4

Also disable --progress.
It is not disabled by default for backward compatibility,
but solves the problem of lots of progress lines
in the downloadable raw output:
https://github.com/actions/checkout/pull/1067

.github/workflows/node-docs.yml

@@ -14,7 +14,9 @@ jobs:
   generate:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
+        with:
+          show-progress: false
 
       - name: Use Node.js 18.x
         uses: actions/setup-node@v3