fix: update phpunit.xml schema for phpunit 12 compatibility

Author: ChiragAgg5k

phpunit.xml

@@ -1,16 +1,16 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit bootstrap="vendor/autoload.php"
-    colors="true"
-    verbose="true"
-    stopOnFailure="false">
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/12.0/phpunit.xsd"
+    bootstrap="vendor/autoload.php"
+    colors="true">
     <testsuites>
         <testsuite name="Utopia Agents Test Suite">
             <directory>tests</directory>
         </testsuite>
     </testsuites>
-    <coverage>
+    <source>
         <include>
             <directory suffix=".php">src/</directory>
         </include>
-    </coverage>
-</phpunit>
+    </source>
+</phpunit>