[composer] Set dependencies for 4.0.0-beta3 release.

Author: Łukasz Serwatka

composer.json

@@ -15,7 +15,7 @@
     "require": {
         "php": "^7.4",
         "ext-json": "*",
-        "ibexa/core": "^4.0@dev",
+        "ibexa/core": "^4.0",
         "netgen/query-translator": "^1.0.2",
         "symfony/http-kernel": "^5.0",
         "symfony/dependency-injection": "^5.0",
@@ -24,7 +24,7 @@
         "symfony/framework-bundle": "^5.0"
     },
     "require-dev": {
-        "ibexa/doctrine-schema": "^4.0@dev",
+        "ibexa/doctrine-schema": "^4.0",
         "phpunit/phpunit": "^8.2",
         "matthiasnoback/symfony-dependency-injection-test": "^4.1",
         "ibexa/code-style": "^1.0"