update the ci pnpm workflow for shell-tool-mcp to use corepack for pnpm versioning (#10115)

This updates the CI workflows for shell-tool-mcp to use the pnpm version
from package.json and print it in the build for verification.

I have read the CLA Document and I hereby sign the CLA

.github/workflows/shell-tool-mcp-ci.yml

@@ -35,6 +35,15 @@ jobs:
           node-version: ${{ env.NODE_VERSION }}
           cache: "pnpm"
 
+      - name: Enable Corepack
+        run: corepack enable
+
+      - name: Activate pnpm from package.json
+        run: corepack prepare --activate
+
+      - name: Verify pnpm version
+        run: pnpm --version
+
       - name: Install dependencies
         run: pnpm install --frozen-lockfile