Plugin doesn't work with napari>=0.5.0

Hi all,

I was trying to update some environments with the latest napari version and where this plugin is installed.
However, that is not possible because this plugin currently requires napari<0.5 as stated [here](https://github.com/matplotlib/napari-matplotlib/blob/c70ad73c23a4e1978506eab4caa06bdc577577b8/setup.cfg#L31). Any plans to have it functional with latest napari versions?