fix: restore PHPUnit 9.6 compatibility after rebase

- Reverted phpunit.xml.dist to PHPUnit 9.3 schema (compatible with PHPUnit 9.6)
- Changed HarTest to use @dataProvider docblock instead of PHP 8 attributes
- Changed fixtureDataProvider from static to instance method

The rebase introduced PHPUnit 12.5 schema and PHP 8 attribute syntax which
are not compatible with the current PHPUnit 9.6 version used in the project.

Author: claude

phpunit.xml.dist

@@ -1,6 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" backupGlobals="false" bootstrap="vendor/autoload.php" colors="true" processIsolation="false" stopOnFailure="false" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/12.5/phpunit.xsd" cacheDirectory=".phpunit.cache" backupStaticProperties="false">
-  <coverage>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" backupGlobals="false" backupStaticAttributes="false" bootstrap="vendor/autoload.php" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true" processIsolation="false" stopOnFailure="false" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
+  <coverage processUncoveredFiles="true">
+    <include>
+      <directory suffix=".php">./src</directory>
+    </include>
     <report>
       <clover outputFile="build/logs/clover.xml"/>
     </report>
@@ -16,9 +19,4 @@
   <logging>
     <junit outputFile="build/logs/results.xml"/>
   </logging>
-  <source>
-    <include>
-      <directory suffix=".php">./src</directory>
-    </include>
-  </source>
 </phpunit>

tests/src/Unit/HarTest.php

@@ -8,14 +8,14 @@
 use Deviantintegral\Har\Har;
 use Deviantintegral\Har\Log;
 use Deviantintegral\Har\Serializer;
-use PHPUnit\Framework\Attributes\DataProvider;
 
 class HarTest extends HarTestBase
 {
     /**
      * Tests deserializing and reserializing a complete HAR file.
+     *
+     * @dataProvider fixtureDataProvider
      */
-    #[DataProvider('fixtureDataProvider')]
     public function testExportedFixture(string $id, Har $har)
     {
         $repository = $this->getHarFileRepository();
@@ -28,9 +28,9 @@ public function testExportedFixture(string $id, Har $har)
         $this->assertEquals($jsonDecode, json_decode($serialized, true));
     }
 
-    public static function fixtureDataProvider()
+    public function fixtureDataProvider()
     {
-        $repository = new \Deviantintegral\Har\Repository\HarFileRepository(__DIR__.'/../../fixtures');
+        $repository = $this->getHarFileRepository();
 
         foreach ($repository->loadMultiple() as $id => $har) {
             yield [$id, $har];