ci: use the Node 24 pnpm setup action

Upgrade the immutable pnpm/action-setup pin from v4 to v6.0.9 so the action itself runs on Node 24 and the successful CI workflow completes without GitHub's Node 20 deprecation warning.

Verified the peeled commit SHA against the pnpm/action-setup repository and confirmed its action metadata declares the node24 runtime.

Author: DeepWiki Dev

.github/workflows/test.yml

@@ -33,7 +33,7 @@ jobs:
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
       - name: Set up pnpm
-        uses: pnpm/action-setup@b906affcce14559ad1aafd4ab0e942779e9f58b1 # v4
+        uses: pnpm/action-setup@0ebf47130e4866e96fce0953f49152a61190b271 # v6.0.9
         with:
           version: 10