chore:(deps): bump @types/node from 15.9.0 to 15.12.0 in /explorer (#17738)

Bumps [@types/node](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/node) from 15.9.0 to 15.12.0.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/node)

---
updated-dependencies:
- dependency-name: "@types/node"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

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

explorer/package-lock.json

@@ -3374,9 +3374,9 @@
       "integrity": "sha512-tHq6qdbT9U1IRSGf14CL0pUlULksvY9OZ+5eEgl1N7t+OA3tGvNpxJCzuKQlsNgCVwbAs670L1vcVQi8j9HjnA=="
     },
     "@types/node": {
-      "version": "15.9.0",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-15.9.0.tgz",
-      "integrity": "sha512-AR1Vq1Ei1GaA5FjKL5PBqblTZsL5M+monvGSZwe6sSIdGiuu7Xr/pNwWJY+0ZQuN8AapD/XMB5IzBAyYRFbocA=="
+      "version": "15.12.0",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-15.12.0.tgz",
+      "integrity": "sha512-+aHJvoCsVhO2ZCuT4o5JtcPrCPyDE3+1nvbDprYes+pPkEsbjH7AGUCNtjMOXS0fqH14t+B7yLzaqSz92FPWyw=="
     },
     "@types/normalize-package-data": {
       "version": "2.4.0",

explorer/package.json

@@ -19,7 +19,7 @@
     "@types/chart.js": "^2.9.32",
     "@types/classnames": "^2.3.1",
     "@types/jest": "^26.0.23",
-    "@types/node": "^15.9.0",
+    "@types/node": "^15.12.0",
     "@types/react": "^17.0.9",
     "@types/react-dom": "^17.0.6",
     "@types/react-router-dom": "^5.1.7",