CI: Cache compiled JS assets for all e2e jobs

.github/workflows/end2end-test.yml

@@ -16,8 +16,31 @@ concurrency:
     cancel-in-progress: true
 
 jobs:
+    build-assets:
+        name: Build JavaScript assets for e2e tests tests
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+              with:
+                  show-progress: ${{ runner.debug == '1' && 'true' || 'false' }}
+
+            - name: Setup Node.js and install dependencies
+              uses: ./.github/setup-node
+
+            - name: Run build scripts
+              run: npm run build
+
+            - name: Upload built JavaScript assets
+              uses: actions/upload-artifact@65462800fd760344b1a7b4382951275a0abb4808 # v4.3.3
+              with:
+                  name: build-assets
+                  path: |
+                      ./build/
+                      ./build-module/
+
     e2e-playwright:
         name: Playwright - ${{ matrix.part }}
+        needs: [build-assets]
         runs-on: ubuntu-latest
         if: ${{ github.repository == 'WordPress/gutenberg' || github.event_name == 'pull_request' }}
         strategy:
@@ -34,8 +57,14 @@ jobs:
             - name: Setup Node.js and install dependencies
               uses: ./.github/setup-node
 
-            - name: Npm build
-              run: npm run build
+            - name: Download built JavaScript assets
+              uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4.1.8
+              with:
+                  name: build-assets
+
+            - name: Build packages
+              run: |
+                  node ./bin/packages/build.js
 
             - name: Install Playwright dependencies
               run: |