Using VSCode extensions: how to configure import path for PySide6 classes

[s.cook]

I'm developing QML modules in VSCode and I've started using the Qt extensions. I'm getting lots of spurious warnings about unrecognised imports. These relate to PySide6 classes in the same VSCode project (regular imports of Qt classes are ok). The PySide6 classes are imported using the @QmlElement decorator, and this mechanism works at runtime but isn't recognised by qmllint or qmlls. How do I configure these Qt tools to recognise the imports from Python? (I've tried adding the path to the Python files' folder, not effective.)