Backport PR matplotlib#26581: Deduplicate test for toolbar button icon LA mode.

Author: timhoffm

lib/matplotlib/tests/test_backends_interactive.py

@@ -206,10 +206,6 @@ def check_alt_backend(alt_backend):
 
     assert fig.canvas.manager.get_window_title() == "Figure 1"
 
-    if mpl.rcParams["toolbar"] == "toolmanager":
-        # test toolbar button icon LA mode see GH issue 25174
-        _test_toolbar_button_la_mode_icon(fig)
-
     if mpl.rcParams["toolbar"] == "toolmanager":
         # test toolbar button icon LA mode see GH issue 25174
         _test_toolbar_button_la_mode_icon(fig)