chore: update github artifact actions (#596)

Author: renovate-bot

.github/workflows/release-ruby-wrapper.yml

@@ -72,7 +72,7 @@ jobs:
           bundle exec rake ${{ matrix.platform_tasks }}
 
       - name: Upload Binaries as Artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           name: ${{ matrix.artifact_name }}
           path: ${{ matrix.artifact_path }}
@@ -100,7 +100,7 @@ jobs:
           working-directory: 'spannerlib/wrappers/spannerlib-ruby'
 
       - name: Download all binaries
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v6
         with:
           # No name means it downloads ALL artifacts from this workflow
           # The binaries will be placed in their original paths