build(deps-dev): Update symfony/event-dispatcher requirement

Updates the requirements on [symfony/event-dispatcher](https://github.com/symfony/event-dispatcher) to permit the latest version.
- [Release notes](https://github.com/symfony/event-dispatcher/releases)
- [Changelog](https://github.com/symfony/event-dispatcher/blob/5.4/CHANGELOG.md)
- [Commits](symfony/event-dispatcher@v4.4.0...v5.4.3)

---
updated-dependencies:
- dependency-name: symfony/event-dispatcher
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

tests/integration/composer.json

@@ -5,7 +5,7 @@
         "guzzlehttp/guzzle": "7.4.2",
         "jarnaiz/behat-junit-formatter": "^1.3",
         "sabre/dav": "4.3.1",
-        "symfony/event-dispatcher": "~4.4"
+        "symfony/event-dispatcher": "~5.4"
     },
     "autoload": {
         "psr-0": {