Don't keep circular reference to figure

Author: dstansby

src/napari_matplotlib/base.py

@@ -48,7 +48,7 @@ def __init__(self, napari_viewer: napari.viewer.Viewer):
 
         self.viewer = napari_viewer
         self.canvas = FigureCanvas()
-        self.canvas.widget = self
+        # self.canvas.widget = self
 
         self.canvas.figure.patch.set_facecolor("none")
         self.canvas.figure.set_layout_engine("constrained")