Build scratch-gui as part of deployment

Author: chrisroos

.github/workflows/deploy.yml

@@ -118,6 +118,14 @@ jobs:
           # Defaults to the user or organization that owns the workflow file
           scope: "@RaspberryPiFoundation"
 
+      - name: Install scratch-gui code
+        run: yarn install --immutable
+        working-directory: scratch
+
+      - name: Build scratch-gui
+        run: yarn build
+        working-directory: scratch
+
       - name: Install code
         run: yarn install --immutable
         env: