chore: remove configuration prod from build:demo for debug

Author: pubuzhixing8

package-lock.json

@@ -7,7 +7,7 @@
     "ng": "ng",
     "start": "ng serve demo",
     "build": "ng build slate-angular --configuration production && cpx \"./packages/src/**/*.scss\" ./dist/",
-    "build:demo": "ng build demo --configuration production",
+    "build:demo": "ng build demo",
     "pub": "npm run build && cd dist && npm publish --access public",
     "pub-next": "npm run build && cd dist && npm publish --tag next --access public",
     "patch": "cd packages && npm version patch",