chore: revert accidentally checked-in webpack 5 deps

package.json

@@ -95,13 +95,10 @@
     "vue-template-compiler": "^2.5.16",
     "vuepress": "^0.14.2",
     "vuepress-theme-vue": "^1.1.0",
-    "webpack": "^5.0.0-0",
+    "webpack": "^4.1.0",
     "webpack-cli": "^3.2.0",
     "webpack-dev-server": "^3.1.1",
     "webpack-merge": "^4.1.2",
     "yorkie": "^1.0.3"
-  },
-  "resolutions": {
-    "webpack": "^5.0.0-0"
   }
 }