Upgrade download-artifact action

PiperOrigin-RevId: 719204519

Author: torsm

.github/workflows/build.yml

@@ -259,7 +259,7 @@ jobs:
       - uses: actions/checkout@v3
       - name: Download installers from GitHub artifacts
         id: download
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           path: ~/_artifacts
       - name: Merge artifacts