Bump core-js from 3.12.1 to 3.15.2

Bumps [core-js](https://github.com/zloirock/core-js/tree/HEAD/packages/core-js) from 3.12.1 to 3.15.2.
- [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/v3.15.2/packages/core-js)

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

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

package.json

@@ -251,7 +251,7 @@
     "chai": "^4.3.4",
     "chalk": "^4.1.1",
     "copy-webpack-plugin": "^9.0.1",
-    "core-js": "^3.12.1",
+    "core-js": "^3.15.2",
     "cross-env": "^7.0.3",
     "css-loader": "^5.2.5",
     "del": "^6.0.0",

yarn.lock

@@ -3839,10 +3839,10 @@ core-js@^2.4.0, core-js@^2.5.0:
   resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.6.11.tgz#38831469f9922bded8ee21c9dc46985e0399308c"
   integrity sha512-5wjnpaT/3dV+XB4borEsnAYQchn00XSgTAWKDkEqv+K8KevjbzmofK6hfJ9TZIlpj2N0xQpazy7PiRQiWHqzWg==
 
-core-js@^3.12.1, core-js@^3.6.5:
-  version "3.12.1"
-  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.12.1.tgz#6b5af4ff55616c08a44d386f1f510917ff204112"
-  integrity sha512-Ne9DKPHTObRuB09Dru5AjwKjY4cJHVGu+y5f7coGn1E9Grkc3p2iBwE9AI/nJzsE29mQF7oq+mhYYRqOMFN1Bw==
+core-js@^3.15.2, core-js@^3.6.5:
+  version "3.15.2"
+  resolved "https://registry.yarnpkg.com/core-js/-/core-js-3.15.2.tgz#740660d2ff55ef34ce664d7e2455119c5bdd3d61"
+  integrity sha512-tKs41J7NJVuaya8DxIOCnl8QuPHx5/ZVbFo1oKgVl1qHFBBrDctzQGtuLjPpRdNTWmKPH6oEvgN/MUID+l485Q==
 
 core-util-is@1.0.2, core-util-is@~1.0.0:
   version "1.0.2"