Fix test_catch_exceptions_in_virtual_methods for pyside6

The latest release seems to have changed the message:

```
ValueError: Error calling Python override of QObject::event(): mistakes were made'
```

tests/test_exceptions.py

@@ -59,7 +59,7 @@ def test_exceptions(qtbot):
             expected_lines = [
                 "*RuntimeError: original error",
                 "*app.sendEvent*",
-                "*ValueError: mistakes were made*",
+                "*ValueError:*mistakes were made*",
                 "*1 failed*",
             ]
         else: