Update version restrictions to supported versions

composer.json

@@ -16,23 +16,21 @@
     }
   ],
   "require": {
-    "php": ">=5.4.0",
-    "symfony/framework-bundle": "^2.6|^3.0|^4.0|^5.0",
-    "doctrine/dbal": "^2.5",
-    "doctrine/orm": "^2.5"
+    "php": ">=7.4",
+    "doctrine/dbal": "^3.1.4",
+    "doctrine/orm": "^2.6",
+    "symfony/framework-bundle": "^4.4|^5.4|^6.0"
   },
   "require-dev": {
-    "php": ">=5.6.0",
     "ext-pdo": "*",
     "ext-pdo_sqlite": "*",
-    "symfony/symfony": "^3.0|^4.0|^5.0",
-    "doctrine/doctrine-bundle": "^1.6",
-    "doctrine/doctrine-fixtures-bundle": "^2.2",
-    "sensio/framework-extra-bundle": "^3.0.2",
+    "data-dog/pager-bundle": "^0.2",
+    "doctrine/doctrine-bundle": "^2.5",
+    "doctrine/doctrine-fixtures-bundle": "^3.4",
     "knplabs/knp-menu-bundle": "^2.0",
     "knplabs/knp-time-bundle": "^1.3",
-    "data-dog/pager-bundle": "^0.2",
-    "phpunit/phpunit": "~4.7.0"
+    "sensio/framework-extra-bundle": "^5.6",
+    "symfony/symfony": "^4.4|^5.4|^6.0"
   },
   "autoload": {
     "psr-4": {