bump symfony/config requirement to 7.3

Author: xabbuh

src/Symfony/Bundle/FrameworkBundle/composer.json

@@ -20,7 +20,7 @@
         "composer-runtime-api": ">=2.1",
         "ext-xml": "*",
         "symfony/cache": "^6.4|^7.0",
-        "symfony/config": "^6.4|^7.0",
+        "symfony/config": "^7.3",
         "symfony/dependency-injection": "^7.2",
         "symfony/deprecation-contracts": "^2.5|^3",
         "symfony/error-handler": "^6.4|^7.0",