fix: add missing dependency postcss-safe-parser

Author: afriestad

package.json

@@ -47,6 +47,7 @@
     "optimize-css-assets-webpack-plugin": "^5.0.3",
     "postcss-flexbugs-fixes": "^3.3.0",
     "postcss-loader": "2.1.5",
+    "postcss-safe-parser": "^4.0.1",
     "promise": "8.0.1",
     "prompt": "1.0.0",
     "react-dev-utils": "6.1.1",