Resolve 2 warnings in CI that remain after recent audit

[willingc]

Down to 2 items as described by Peter above:

• WARNING: Attribute Qt::AA_ShareOpenGLContexts must be set before QCoreApplication is created.
• WARNING: Notice reading .OBJ: material properties are ignored.

Originally posted by @willingc in #596

[psobolewskiPhD]

I think we're down to:
WARNING: Attribute Qt::AA_ShareOpenGLContexts must be set before QCoreApplication is created.
Which does appear to be set in if __name__ ...:
QtWidgets.QApplication.setAttribute(Qt.ApplicationAttribute.AA_ShareOpenGLContexts)
https://github.com/napari/napari/blob/838ce4cc6b5cd77a5197102ee7e69e57d7a0358d/examples/multiple_viewer_widget.py#L426
and
WARNING: Notice reading .OBJ: material properties are ignored.
which relates to the dataset being loaded, the material properties are un-supported, see:
https://napari.org/stable/gallery/surface_multi_texture.html#load-the-model

Originally posted by @psobolewskiPhD in #596