Update AstHasher for parser v5 compatibility

Changed the ParserFactory creation method to use the newest supported version in AstHasher. Updated the expected hash value in the unit test to align with the new parser's output.

Author: o0h

Diff for: src/External/AstHasher.php

@@ -17,7 +17,7 @@ final class AstHasher implements AstHasherInterface
 
     public function __construct()
     {
-        $this->parser = (new ParserFactory())->create(ParserFactory::PREFER_PHP7);
+        $this->parser = (new ParserFactory())->createForNewestSupportedVersion();
         $this->dumper = new NodeDumper();
     }
 

Diff for: tests/unit/External/AstHasherTest.php

@@ -35,7 +35,7 @@ public function getLongString($seed): string
              }
             CODE;
         $actual = $this->subject->get($source);
-        $expected = 'abcd814e2805dc8935a669bccd6671a7';
+        $expected = 'e972738f82f2733237099fa4f141582f';
         $this->assertSame($expected, $actual);
     }