[5.4] Allow PhpUnitBridge v7

Author: nicolas-grekas

composer.json

@@ -44,7 +44,6 @@
         "symfony/uid": "^5.1|^6.0"
     },
     "conflict": {
-        "phpunit/phpunit": "<5.4.3",
         "symfony/console": "<4.4",
         "symfony/dependency-injection": "<4.4",
         "symfony/doctrine-bridge": "<5.4.21|>=6,<6.2.7",