test: migrate yarn modern examples to corepack

.github/workflows/example-yarn-modern-pnp.yml

@@ -13,7 +13,7 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-
+      - run: corepack enable yarn # experimental - see https://nodejs.org/docs/latest/api/corepack.html
       - name: Custom Yarn command
         uses: ./
         with:

.github/workflows/example-yarn-modern.yml

@@ -13,7 +13,7 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-
+      - run: corepack enable yarn # experimental - see https://nodejs.org/docs/latest/api/corepack.html
       - name: Custom Yarn command
         uses: ./
         with:

examples/yarn-modern-pnp/README.md

@@ -1,3 +1,11 @@
 # example: yarn-modern-pnp
 
-This example demonstrates installing dependencies using [Yarn Modern (version 2 and later)](https://yarnpkg.com/) with [Plug'n'Play](https://yarnpkg.com/features/pnp) turned on.
+This example demonstrates installing dependencies using [Yarn Modern v4](https://yarnpkg.com/) with [corepack](https://yarnpkg.com/corepack) enabled and the default configuration of [Plug'n'Play](https://yarnpkg.com/features/pnp) enabled.
+
+Run locally with:
+
+```shell
+corepack enable yarn
+yarn
+yarn test
+```

examples/yarn-modern/.yarnrc.yml

@@ -1,3 +1 @@
 nodeLinker: node-modules
-
-yarnPath: .yarn/releases/yarn-4.6.0.cjs

examples/yarn-modern/README.md

@@ -1,3 +1,11 @@
 # example: yarn-modern
 
-This example demonstrates installing dependencies using [Yarn Modern (version 2 and later)](https://yarnpkg.com/).
+This example demonstrates installing dependencies using [Yarn Modern v4](https://yarnpkg.com/) with [corepack](https://yarnpkg.com/corepack) enabled and the configuration option `nodeLinker: node-modules` selected.
+
+Run locally with:
+
+```shell
+corepack enable yarn
+yarn
+yarn test
+```