Adding compatibility with dompdf 3.0

I didn't test this. But https://github.com/dompdf/dompdf/releases/tag/v3.0.0 looks like there were no breaking changes.

composer.json

@@ -37,7 +37,7 @@
     ],
     "require": {
         "php": "^8.1",
-        "dompdf/dompdf": "^1.0.0 || ^2.0.0",
+        "dompdf/dompdf": "^1.0.0 || ^2.0.0 || ^3.0.0",
         "symfony/config": "^6.4 || ^7.0",
         "symfony/dependency-injection": "^6.4 || ^7.0",
         "symfony/event-dispatcher-contracts": "^1.1 || ^2.0 || ^3.0",