removed core-js dependency.

package.json

@@ -15,7 +15,6 @@
     "@kintone/rest-api-client": "^5.7.3",
     "angular-expressions": "^1.4.3",
     "clsx": "^2.1.1",
-    "core-js": "^3.42.0",
     "dayjs": "^1.11.13",
     "docxtemplater": "^3.63.2",
     "file-saver": "^2.0.5",