[PHP]: Update phpstan/phpstan-symfony requirement from 1.4.6 to 1.4.7

Updates the requirements on [phpstan/phpstan-symfony](https://github.com/phpstan/phpstan-symfony) to permit the latest version.
- [Release notes](https://github.com/phpstan/phpstan-symfony/releases)
- [Commits](phpstan/phpstan-symfony@1.4.6...1.4.7)

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

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

composer.json

@@ -35,7 +35,7 @@
         "phpstan/phpstan": "1.11.10",
         "phpstan/phpstan-doctrine": "1.5.0",
         "phpstan/phpstan-phpunit": "1.4.0",
-        "phpstan/phpstan-symfony": "1.4.6",
+        "phpstan/phpstan-symfony": "1.4.7",
         "rector/rector": "1.2.2",
         "roave/security-advisories": "dev-master",
         "serendipity_hq/rector-config": "^1.0",