Fix gtk4 incorrect import.

anntzer · anntzer · commit 84aa97e4f2be · 2022-04-28T10:33:24.000+02:00
There's no backend_gtk module.
diff --git a/lib/matplotlib/backends/backend_gtk4.py b/lib/matplotlib/backends/backend_gtk4.py
@@ -26,7 +26,7 @@
     _BackendGTK, _FigureManagerGTK, _NavigationToolbar2GTK,
     TimerGTK as TimerGTK4,
 )
-from .backend_gtk import backend_version  # noqa: F401 # pylint: disable=W0611
+from ._backend_gtk import backend_version  # noqa: F401 # pylint: disable=W0611
 
 
 class FigureCanvasGTK4(Gtk.DrawingArea, FigureCanvasBase):

Original file line number	Diff line number	Diff line change
`@@ -26,7 +26,7 @@`
`26`	`26`	`_BackendGTK, _FigureManagerGTK, _NavigationToolbar2GTK,`
`27`	`27`	`TimerGTK as TimerGTK4,`
`28`	`28`	`)`
`29`		`-from .backend_gtk import backend_version # noqa: F401 # pylint: disable=W0611`
	`29`	`+from ._backend_gtk import backend_version # noqa: F401 # pylint: disable=W0611`
`30`	`30`
`31`	`31`
`32`	`32`	`class FigureCanvasGTK4(Gtk.DrawingArea, FigureCanvasBase):`