try to use pnpm action setup and recommend usign corepack

.github/workflows/ci.yml

@@ -13,12 +13,12 @@ jobs:
         with:
           java-version: 17
           java-package: jre
-      - name: Install pnpm
-        run: npm i -g pnpm@9.0.4
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 22
           # cache: "pnpm"
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
       - run: pnpm install
       - run: pnpm check-build
       - run: pnpm build-playground

CONTRIBUTING.md

@@ -2,7 +2,7 @@
 
 After forking the repository, run the following commands to get started:
 
-0. Ensure you have [Node.js](https://nodejs.org) and `pnpm` installed. To install pnpm run `npm i -g pnpm@9.0.4`.
+0. Ensure you have [Node.js](https://nodejs.org) installed. Enable corepack with `corepack enable`.
 1. Install dependencies: `pnpm i`
 2. Start the project in development mode: `pnpm start`
 3. Read the [Tasks Categories](#tasks-categories) and [Workflow](#workflow) sections below