chore:(deps): bump @testing-library/user-event in /explorer (#11217)

Bumps [@testing-library/user-event](https://github.com/testing-library/user-event) from 12.0.13 to 12.0.15.
- [Release notes](https://github.com/testing-library/user-event/releases)
- [Changelog](https://github.com/testing-library/user-event/blob/master/CHANGELOG.md)
- [Commits](https://github.com/testing-library/user-event/compare/v12.0.13...v12.0.15)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

explorer/package-lock.json

@@ -2689,9 +2689,9 @@
       }
     },
     "@testing-library/user-event": {
-      "version": "12.0.13",
-      "resolved": "https://registry.npmjs.org/@testing-library/user-event/-/user-event-12.0.13.tgz",
-      "integrity": "sha512-JvodPV7CGl2Izf/qWS+vAVKBB1ZNAPGEacabfEeLGfafLmiqXoGJCxNZC1ml3mNTj9tTsIjouHGc42gvlyRTtQ==",
+      "version": "12.0.15",
+      "resolved": "https://registry.npmjs.org/@testing-library/user-event/-/user-event-12.0.15.tgz",
+      "integrity": "sha512-B+f8lpty7Nnq0i06FBGPDWT+asnHaudpmYBKDw7wqIq5xpUdzfDBSOdlcwRNneM3XrD0RsOZE9BXuDwr5pwsvw==",
       "requires": {
         "@babel/runtime": "^7.10.2"
       },

explorer/package.json

@@ -7,7 +7,7 @@
     "@solana/web3.js": "^0.63.1",
     "@testing-library/jest-dom": "^5.11.1",
     "@testing-library/react": "^10.4.7",
-    "@testing-library/user-event": "^12.0.13",
+    "@testing-library/user-event": "^12.0.15",
     "@types/bs58": "^4.0.1",
     "@types/jest": "^26.0.7",
     "@types/node": "^14.0.25",