Fix trailing whitespace in test

Co-authored-by: OskarStark <995707+OskarStark@users.noreply.github.com>

Author: Copilot

src/agent/tests/Toolbox/AgentProcessorTest.php

@@ -247,14 +247,14 @@ public function testSourcesEndUpInResultMetadataWithStreaming()
             ->willReturn(new ToolResult($toolCall, 'Response based on the two articles.', [$source1, $source2]));
 
         $messageBag = new MessageBag();
-        
+
         // Create a generator that yields chunks and then a ToolCallResult
         $generator = (function () use ($toolCall) {
             yield 'chunk1';
             yield 'chunk2';
             yield new ToolCallResult($toolCall);
         })();
-        
+
         $result = new GenericStreamResult($generator);
 
         $agent = $this->createMock(AgentInterface::class);
@@ -275,7 +275,7 @@ public function testSourcesEndUpInResultMetadataWithStreaming()
         foreach ($output->getResult()->getContent() as $chunk) {
             $content .= $chunk;
         }
-        
+
         // After consuming the stream, metadata should be available
         $metadata = $output->getResult()->getMetadata();
         $this->assertTrue($metadata->has('sources'));