Update build script to also build Elsa.Core.Designer client assets

.github/workflows/packages.yml

@@ -21,6 +21,11 @@ jobs:
           git branch --remote --contains | grep origin/v3
       - name: Set VERSION variable
         run: echo "VERSION=3.0.0-preview.${{github.run_number}}" >> $GITHUB_ENV
+      - name: Build designer package
+        working-directory: ./src/modules/Elsa.Workflows.Designer
+        run: |
+          npm install --force
+          npm run build
       - name: Build
         run: dotnet build --configuration Release /p:Version=${VERSION}
       - name: Test