deps(dev): bump @types/react-dom from 18.2.20 to 18.2.21

Bumps [@types/react-dom](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/react-dom) from 18.2.20 to 18.2.21.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/react-dom)

---
updated-dependencies:
- dependency-name: "@types/react-dom"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

package.json

@@ -77,7 +77,7 @@
     "@types/mocha": "^10.0.6",
     "@types/node-fetch": "^2.6.11",
     "@types/react": "^18.2.63",
-    "@types/react-dom": "^18.2.20",
+    "@types/react-dom": "^18.2.21",
     "@types/split2": "^4.2.3",
     "@types/tmp": "^0.2.6",
     "@typescript-eslint/eslint-plugin": "^5.62.0",