Remove obsoleted codes

Author: MasaGon

package.json

@@ -6,8 +6,7 @@
   "private": true,
   "scripts": {
     "dev": "cross-env NODE_ENV=development nuxt-ts",
-    "build": "yarn prebuild && nuxt-ts build",
-    "prebuild": "node pre_build_script/swEnvBuild.js",
+    "build": "nuxt-ts build",
     "test:unit": "jest --config jest.config.js",
     "start": "nuxt-ts start",
     "generate": "nuxt-ts generate",