chore: remove unnecessary @types/classnames (#665)

Author: JounQin

package.json

@@ -60,7 +60,6 @@
     "shallowequal": "^1.1.0"
   },
   "devDependencies": {
-    "@types/classnames": "^2.2.9",
     "@types/enzyme": "^3.10.5",
     "@types/jest": "^26.0.3",
     "@types/react": "^17.0.35",