Store WordPress "build" directory as an artifact to enable live previews with Playground

.github/workflows/build.yml

@@ -0,0 +1,67 @@
+name: Build WordPress
+
+on:
+  pull_request:
+  workflow_dispatch:
+
+# Cancels all previous workflow runs for pull requests that have not completed.
+concurrency:
+  # The concurrency group contains the workflow name and the branch name for pull requests
+  # or the commit hash for any other events.
+  group: ${{ github.workflow }}-${{ github.event_name == 'pull_request' && github.head_ref || github.sha }}
+  cancel-in-progress: true
+
+# Disable permissions for all available scopes by default.
+# Any needed permissions should be configured at the job level.
+permissions: {}
+
+# Exposes WordPress builds as a GitHub artifact to enable 
+# previewing Pull Requests inside WordPress Playground.
+# 
+# @see https://github.com/WordPress/wordpress-playground/pull/700
+# @see https://github.com/WordPress/wordpress-develop/pull/5481
+jobs:
+  build-wordpress:
+    name: Upload WordPress build as an artifact
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    timeout-minutes: 20
+    if: ${{ github.repository == 'WordPress/wordpress-develop' || github.event_name == 'pull_request' }}
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
+        with:
+          show-progress: ${{ runner.debug == '1' && 'true' || 'false' }}
+
+      - name: Set up Node.js
+        uses: actions/setup-node@5e21ff4d9bc1a8cf6de233a3057d20ec6b3fb69d # v3.8.1
+        with:
+          node-version-file: '.nvmrc'
+          cache: npm
+
+      - name: Log debug information
+        run: |
+          npm --version
+          node --version
+          curl --version
+          git --version
+          svn --version
+
+      - name: Install npm Dependencies
+        run: npm ci
+
+      - name: Build WordPress
+        run: npm run build
+
+      - name: Zip WordPress build
+        run: zip -r build.zip build/*
+
+      - name: Upload the build directory as GitHub artifact
+        uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
+        if: always()
+        with:
+            name: wordpress-build-${{ github.event_name == 'pull_request' && github.event.number || github.sha }}
+            path: build.zip
+            if-no-files-found: error