build(deps): bump core-js from 2.6.9 to 3.8.1

Bumps [core-js](https://github.com/zloirock/core-js) from 2.6.9 to 3.8.1.
- [Release notes](https://github.com/zloirock/core-js/releases)
- [Changelog](https://github.com/zloirock/core-js/blob/master/CHANGELOG.md)
- [Commits](zloirock/core-js@v2.6.9...v3.8.1)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package.json

@@ -24,7 +24,7 @@
     "@uirouter/core": "6.0.5",
     "@uirouter/rx": "0.6.5",
     "@uirouter/visualizer": "^7.2.1",
-    "core-js": "^2.5.7",
+    "core-js": "^3.8.1",
     "rxjs": "^6.6.3",
     "rxjs-compat": "^6.6.3",
     "ts-helpers": "^1.1.2",

yarn.lock

@@ -3161,10 +3161,10 @@ [email protected]:
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.6.4.tgz#440a83536b458114b9cb2ac1580ba377dc470647"
   integrity sha512-4paDGScNgZP2IXXilaffL9X7968RuvwlkK3xWtZRVqgd8SYNiVKRJvkFd1aqqEuPfN7E68ZHEp9hDj6lHj4Hyw==
 
-core-js@^2.5.7:
-  version "2.6.9"
-  resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.6.9.tgz#6b4b214620c834152e179323727fc19741b084f2"
-  integrity sha512-HOpZf6eXmnl7la+cUdMnLvUxKNqLUzJvgIziQ0DiF3JwSImNphIqdGqzj6hIKyX04MmV0poclQ7+wjWvxQyR2A==
+core-js@^3.8.1:
+  version "3.8.1"
+  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.8.1.tgz#f51523668ac8a294d1285c3b9db44025fda66d47"
+  integrity sha512-9Id2xHY1W7m8hCl8NkhQn5CufmF/WuR30BTRewvCXc1aZd3kMECwNZ69ndLbekKfakw9Rf2Xyc+QR6E7Gg+obg==
 
 [email protected], core-util-is@~1.0.0:
   version "1.0.2"