build: remove unused package

Author: kiaking

package.json

@@ -60,7 +60,6 @@
     "chalk": "^4.0.0",
     "conventional-changelog-cli": "^2.0.31",
     "cross-env": "^5.2.0",
-    "cross-spawn": "^6.0.5",
     "css-loader": "^2.1.0",
     "enquirer": "^2.3.5",
     "eslint": "^6.8.0",