ci: fix publish failing in pnpm mode (#2829)

.github/workflows/build.yml

@@ -17,6 +17,10 @@ jobs:
           fetch-depth: 0
       - name: Setup the toolchain
         uses: ./.github/actions/setup-toolchain
+        with:
+          # `npm pack` fails in pnpm mode when using npm 9+ (bundled with Node 18+)
+          # See also: https://github.com/npm/cli/issues/5007
+          node-version: "16"
       - name: Install package dependencies
         run: |
           yarn