update jms serializer bundle to clear readonly keyword problem

composer.json

@@ -50,7 +50,7 @@
     "doctrine/orm": "^2.8",
     "friendsofsymfony/rest-bundle": "^3.0",
     "gedmo/doctrine-extensions": "^3.0",
-    "jms/serializer-bundle": "^3.9",
+    "jms/serializer-bundle": "^4.0",
     "nelmio/api-doc-bundle": "^4.3",
     "nelmio/cors-bundle": "^2.1",
     "sensio/framework-extra-bundle": "^6.1",

symfony.lock

@@ -144,12 +144,6 @@
     "laminas/laminas-code": {
         "version": "4.1.0"
     },
-    "laminas/laminas-eventmanager": {
-        "version": "3.3.1"
-    },
-    "laminas/laminas-zendframework-bridge": {
-        "version": "1.2.0"
-    },
     "nelmio/api-doc-bundle": {
         "version": "3.0",
         "recipe": {