Update design-systems:dev script to build packages (#18073)

The build-style/style.css needs to be rebuilt prior to
running Storybook in watch mode.

This change adds `npm run build:packages` at the start of
the design-systems:dev script to CSS is built prior.

Issue found in #17997

package.json

@@ -198,7 +198,7 @@
 		"test-unit:native": "cd test/native/ && cross-env NODE_ENV=test jest --config ./jest.config.js",
 		"test-unit:native:debug": "cd test/native/ && node --inspect ../../node_modules/.bin/jest --runInBand --config ./jest.config.js",
 		"design-system:build": "npm run build:packages && build-storybook -c ./packages/components/storybook -o ./playground/dist/design-system/components",
-		"design-system:dev": "concurrently \"npm run dev:packages\" \"start-storybook -c ./packages/components/storybook\"",
+		"design-system:dev": "npm run build:packages && concurrently \"npm run dev:packages\" \"start-storybook -c ./packages/components/storybook\"",
 		"playground:build": "npm run build:packages && parcel build playground/src/index.html -d playground/dist",
 		"playground:dev": "concurrently \"npm run dev:packages\" \"parcel playground/src/index.html -d playground/dist\"",
 		"preenv": "npm run check-engines",