style(backend): Fix formatting in test_blocks_dos_vulnerability.py

Co-authored-by: Nicholas Tindle <[email protected]>

🤖 Generated with [Claude Code](https://claude.ai/code)

autogpt_platform/backend/backend/blocks/test/test_blocks_dos_vulnerability.py

@@ -201,9 +201,7 @@ async def test_rejects_text_outside_root(self):
         block = XMLParserBlock()
         invalid_xml = "<root><child>value</child></root> trailing"
 
-        with pytest.raises(
-            ValueError, match="text outside the root element"
-        ):
+        with pytest.raises(ValueError, match="text outside the root element"):
             async for _ in block.run(XMLParserBlock.Input(input_xml=invalid_xml)):
                 pass