Bump core-js from 3.25.3 to 3.26.0 in /vue

Bumps [core-js](https://github.com/zloirock/core-js/tree/HEAD/packages/core-js) from 3.25.3 to 3.26.0.
- [Release notes](https://github.com/zloirock/core-js/releases)
- [Changelog](https://github.com/zloirock/core-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/zloirock/core-js/commits/v3.26.0/packages/core-js)

---
updated-dependencies:
- dependency-name: core-js
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vue/package.json

@@ -18,7 +18,7 @@
     "babel-core": "^6.26.3",
     "babel-loader": "^8.2.5",
     "bootstrap-vue": "^2.21.2",
-    "core-js": "^3.25.3",
+    "core-js": "^3.26.0",
     "html2pdf.js": "^0.10.1",
     "lodash": "^4.17.21",
     "mavon-editor": "^2.10.4",