TST: Remove test_backend_gtk3::test_correct_key

This test has been an expected failure since it was created, and in that
time, `gtk_test_widget_send_key` was never made to work, nor was a
replacement found. In GTK4, that API doesn't exist either.

Author: QuLogic

lib/matplotlib/tests/test_backend_gtk3.py

@@ -5,51 +5,6 @@
 from unittest import mock
 
 
-@pytest.mark.backend("gtk3agg", skip_on_importerror=True)
-def test_correct_key():
-    pytest.xfail("test_widget_send_event is not triggering key_press_event")
-
-    from gi.repository import Gdk, Gtk  # type: ignore[import]
-    fig = plt.figure()
-    buf = []
-
-    def send(event):
-        for key, mod in [
-                (Gdk.KEY_a, Gdk.ModifierType.SHIFT_MASK),
-                (Gdk.KEY_a, 0),
-                (Gdk.KEY_a, Gdk.ModifierType.CONTROL_MASK),
-                (Gdk.KEY_agrave, 0),
-                (Gdk.KEY_Control_L, Gdk.ModifierType.MOD1_MASK),
-                (Gdk.KEY_Alt_L, Gdk.ModifierType.CONTROL_MASK),
-                (Gdk.KEY_agrave,
-                 Gdk.ModifierType.CONTROL_MASK
-                 | Gdk.ModifierType.MOD1_MASK
-                 | Gdk.ModifierType.MOD4_MASK),
-                (0xfd16, 0),   # KEY_3270_Play.
-                (Gdk.KEY_BackSpace, 0),
-                (Gdk.KEY_BackSpace, Gdk.ModifierType.CONTROL_MASK),
-        ]:
-            # This is not actually really the right API: it depends on the
-            # actual keymap (e.g. on Azerty, shift+agrave -> 0).
-            Gtk.test_widget_send_key(fig.canvas, key, mod)
-
-    def receive(event):
-        buf.append(event.key)
-        if buf == [
-                "A", "a", "ctrl+a",
-                "\N{LATIN SMALL LETTER A WITH GRAVE}",
-                "alt+control", "ctrl+alt",
-                "ctrl+alt+super+\N{LATIN SMALL LETTER A WITH GRAVE}",
-                # (No entry for KEY_3270_Play.)
-                "backspace", "ctrl+backspace",
-        ]:
-            plt.close(fig)
-
-    fig.canvas.mpl_connect("draw_event", send)
-    fig.canvas.mpl_connect("key_press_event", receive)
-    plt.show()
-
-
 @pytest.mark.backend("gtk3agg", skip_on_importerror=True)
 def test_save_figure_return():
     from gi.repository import Gtk