chore: reduce CSS watcher noise (#8353)

Author: Lukas742

package.json

@@ -7,7 +7,7 @@
   "license": "Apache-2.0",
   "scripts": {
     "start": "yarn setup && yarn create-cypress-commands-docs && npm-run-all -p start:watcher start:storybook",
-    "start:watcher": "lerna run watch:css",
+    "start:watcher": "lerna run watch:css > /dev/null",
     "start:storybook": "storybook dev -p 6006",
     "setup": "lerna run build:i18n && lerna run build:css && lerna run build:css-bundle && lerna run build:version-info && rimraf node_modules/@types/mocha",
     "build": "yarn setup && tsc --build tsconfig.build.json && lerna run build:client && lerna run build:wrapper",