WebEngine on Linux doesn't render COLRv1 fonts

Chrome supports COLRv1 fonts since Chrome 98 , but they don't render in a QtWebEngine on Linux.

Steps to reproduce:

1. Install PySide6 (provided example is in Python, but I don't think the bug has anything to do with Python binding per se).
2. Download Noto-COLRv1.ttf from https://github.com/googlefonts/noto-emoji/tree/main/fonts.
3. Download attachments.
4. Run python colrv1_test.py and see that nothing is rendered.
5. Open colrv1-test.html in Chrome and see that it renders an emoji.

The bug is not reproducible on Windows or macOS. QtWebEngine on these OSs does support COLRv1.