Update symfony/runtime requirement from ^5.3 to ^5.3 || ^6.0

Updates the requirements on [symfony/runtime](https://github.com/symfony/runtime) to permit the latest version.
- [Release notes](https://github.com/symfony/runtime/releases)
- [Changelog](https://github.com/symfony/runtime/blob/5.4/CHANGELOG.md)
- [Commits](symfony/runtime@v5.3.0...v6.0.0)

---
updated-dependencies:
- dependency-name: symfony/runtime
  dependency-type: direct:production
...

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

Author: dependabot[bot]

composer.json

@@ -25,7 +25,7 @@
         "nyholm/psr7": "^1.4",
         "nyholm/psr7-server": "^1.0",
         "react/http": "^1.5",
-        "symfony/runtime": "^5.3"
+        "symfony/runtime": "^5.3 || ^6.0"
     },
     "require-dev": {
         "infection/infection": "^0.25",