Bump @types/node from 14.14.25 to 15.12.5

Bumps [@types/node](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/node) from 14.14.25 to 15.12.5.
- [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:development
  update-type: version-update:semver-major
...

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

package.json

@@ -31,7 +31,7 @@
   },
   "devDependencies": {
     "@types/jest": "^26.0.23",
-    "@types/node": "^14.14.25",
+    "@types/node": "^15.12.5",
     "jest": "^26.6.3",
     "jest-circus": "^26.6.3",
     "ts-jest": "^26.5.6",