Bump react/promise from 2.8.0 to 2.9.0

Bumps [react/promise](https://github.com/reactphp/promise) from 2.8.0 to 2.9.0.
- [Release notes](https://github.com/reactphp/promise/releases)
- [Changelog](https://github.com/reactphp/promise/blob/2.x/CHANGELOG.md)
- [Commits](reactphp/promise@v2.8.0...v2.9.0)

---
updated-dependencies:
- dependency-name: react/promise
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

composer.json

@@ -13,7 +13,7 @@
     "clue/block-react": "^1.5",
     "phpunit/phpunit": "^9.5",
     "react/event-loop": "^1.2",
-    "react/promise": "^2.8",
+    "react/promise": "^2.9",
     "wyrihaximus/test-utilities": "^5 || ^4 || ^3.7.6"
   },
   "require-dev": {