Add unit test for l shortcut

Since I already had a test for `k`, added a similar test for `l`.

qt/applications/workbench/workbench/plotting/test/test_figureinteraction.py

@@ -724,7 +724,7 @@ def test_click_y_axes_tick_label_launches_y_axes_editor(self, mock_y_editor):
 
         mock_y_editor.assert_called_once()
 
-    def test_keyboard_shortcuts_switch_axes_scale(self):
+    def test_keyboard_shortcut_switch_x_scale(self):
         key_press_event = self._create_mock_key_press_event("k")
         key_press_event.inaxes.get_xscale.return_value = "linear"
         key_press_event.inaxes.get_yscale.return_value = "log"
@@ -740,6 +740,22 @@ def test_keyboard_shortcuts_switch_axes_scale(self):
         key_press_event.inaxes.set_xlim.assert_called_once_with((0, 100))
         key_press_event.inaxes.set_ylim.assert_called_once_with((5, 10))
 
+    def test_keyboard_shortcut_switch_y_scale(self):
+        key_press_event = self._create_mock_key_press_event("l")
+        key_press_event.inaxes.get_xscale.return_value = "linear"
+        key_press_event.inaxes.get_yscale.return_value = "log"
+        key_press_event.inaxes.get_xlim.return_value = (0, 100)
+        key_press_event.inaxes.get_ylim.return_value = (5, 10)
+        key_press_event.inaxes.get_lines.return_value = ["fake_line"]
+        fig_manager = MagicMock()
+        fig_manager.canvas = MagicMock()
+        interactor = FigureInteraction(fig_manager)
+        interactor.on_key_press(key_press_event)
+        key_press_event.inaxes.set_xscale.assert_called_once_with("linear")
+        key_press_event.inaxes.set_yscale.assert_called_once_with("linear")
+        key_press_event.inaxes.set_xlim.assert_called_once_with((0, 100))
+        key_press_event.inaxes.set_ylim.assert_called_once_with((5, 10))
+
     # Private methods
     def _create_mock_fig_manager_to_accept_right_click(self):
         fig_manager = MagicMock()