chore(deps-dev): Bump symfony/event-dispatcher in /build/integration

Bumps [symfony/event-dispatcher](https://github.com/symfony/event-dispatcher) from 5.4.34 to 6.0.19.
- [Release notes](https://github.com/symfony/event-dispatcher/releases)
- [Changelog](https://github.com/symfony/event-dispatcher/blob/7.0/CHANGELOG.md)
- [Commits](symfony/event-dispatcher@v5.4.34...v6.0.19)

---
updated-dependencies:
- dependency-name: symfony/event-dispatcher
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

build/integration/composer.json

@@ -11,6 +11,6 @@
 		"guzzlehttp/guzzle": "^7.8",
 		"phpunit/phpunit": "^9.6",
 		"sabre/dav": "^4.6",
-		"symfony/event-dispatcher": "^5.4"
+		"symfony/event-dispatcher": "^6.0"
 	}
 }