Update symfony/http-kernel requirement from ^6.0 to ^7.1

Updates the requirements on [symfony/http-kernel](https://github.com/symfony/http-kernel) to permit the latest version.
- [Release notes](https://github.com/symfony/http-kernel/releases)
- [Changelog](https://github.com/symfony/http-kernel/blob/7.1/CHANGELOG.md)
- [Commits](symfony/http-kernel@v6.0.0...v7.1.2)

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

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

composer.json

@@ -34,7 +34,7 @@
     "symfony/dependency-injection": "^6.0",
     "symfony/framework-bundle": "^6.0",
     "symfony/http-foundation": "^6.0",
-    "symfony/http-kernel": "^6.0",
+    "symfony/http-kernel": "^7.1",
     "symfony/routing": "^6.0"
   },
   "require-dev": {