Update test_yaml.py

Use correct variable name

Author: granoe668

tests/unit/sdk/test_yaml.py

@@ -8,7 +8,7 @@
 def test_read_missing_file() -> None:
     file_name = "i_do_not_exist.yml"
     dir = here / "test_data"
-    full_path = dir / filename
+    full_path = dir / file_name
     yaml_file = YamlFile(location=full_path)
     yaml_file.load_content()
     assert not yaml_file.valid