Remove postcss dev dependency (Comcast#4056)

Author: nstepien

package-lock.json

@@ -70,7 +70,6 @@
     "jspdf-autotable": "^5.0.7",
     "oxfmt": "0.51.0",
     "playwright": "~1.60.0",
-    "postcss": "^8.5.2",
     "react": "^19.2.5",
     "react-dom": "^19.2.5",
     "tsdown": "^0.22.0",