Update symfony/serializer requirement from ^4.0 to ^5.2

Updates the requirements on [symfony/serializer](https://github.com/symfony/serializer) to permit the latest version.
- [Release notes](https://github.com/symfony/serializer/releases)
- [Changelog](https://github.com/symfony/serializer/blob/5.x/CHANGELOG.md)
- [Commits](symfony/serializer@v4.0.0...v5.2.1)

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

Author: dependabot[bot]

composer.json

@@ -30,7 +30,7 @@
     "symfony/framework-bundle": "^4.0",
     "symfony/http-foundation": "^4.0",
     "symfony/messenger": "^4.2",
-    "symfony/serializer": "^4.0"
+    "symfony/serializer": "^5.2"
   },
   "config": {
     "platform": {