build: update release script

Author: johannesjo

package.json

@@ -10,7 +10,7 @@
     "e2e": "ng e2e",
     "ubl": "npx browserslist@latest --update-db",
     "demo": "run-s demo.build demo.gh-pages",
-    "demo.build": "ng build --aot --prod --base-href='./'",
+    "demo.build": "ng build --aot --configuration production --base-href='./'",
     "demo.gh-pages": "gh-pages -d dist/angular-material-css-vars",
     "lib": "run-s lib.build copy",
     "lib.build": "ng build material-css-vars",
@@ -71,4 +71,4 @@
     "tslint": "~6.1.0",
     "typescript": "~4.8.0"
   }
-}
+}