put back setup to v4 (other at v6 from gist)

Author: Alain Picard

.github/workflows/publish.yaml

@@ -17,7 +17,7 @@ jobs:
           node-version: "24.x"
           registry-url: "https://registry.npmjs.org"
           scope: "@alpic80"
-      - uses: pnpm/action-setup@v6
+      - uses: pnpm/action-setup@v4
       - run: pnpm install --frozen-lockfile
       - run: pnpm typecheck
       - run: pnpm build