ci(website): bump pnpm to 10 to match repo

The root `pnpm-workspace.yaml` added for pnpm 11 build-script approval
breaks pnpm 9, which treats the file as a strict monorepo manifest and
requires a `packages:` field. pnpm 10+ reads it as a general config
file. Matches the other workflows (ci.yml, publish.yml) which already
use pnpm 10. Website's `pnpm-lock.yaml` is lockfile v9.0 which pnpm 10
reads natively.

Author: serhiizhabskiy

.github/workflows/deploy-website.yml

@@ -41,7 +41,7 @@ jobs:
       - name: Setup pnpm
         uses: pnpm/action-setup@v4
         with:
-          version: 9
+          version: 10
 
       - name: Setup Node.js
         uses: actions/setup-node@v4