COH-32151 - Pin workflow action actions/download-artifactv@4 to immutable commit

Author: dhirupandey

.github/workflows/release.yml

@@ -60,7 +60,7 @@ jobs:
           path: ./docs/_build
 
       - name: Download artifact
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e  # v4.2.1
         with:
           name: github-pages
           path: .