UI: Updating Animation Editors snapping from 'Modes' to no icon

Updates the animations editors (NLA, Dope Sheet, Graph editor) to have no icon instead of "Modes" (in absence of icon set).

Pull Request: https://projects.blender.org/blender/blender/pulls/112633

scripts/startup/bl_ui/space_graph.py

@@ -54,8 +54,7 @@ class GRAPH_HT_header(Header):
         sub = row.row(align=True)
         sub.popover(
             panel="GRAPH_PT_snapping",
-            icon='NONE',
-            text="Modes",
+            text="",
         )
 
         row = layout.row(align=True)