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_dopesheet.py

@@ -282,8 +282,7 @@ class DOPESHEET_HT_editor_buttons:
             sub = row.row(align=True)
             sub.popover(
                 panel="DOPESHEET_PT_snapping",
-                icon='NONE',
-                text="Modes",
+                text="",
             )
 
         row = layout.row(align=True)

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)

scripts/startup/bl_ui/space_nla.py

@@ -39,8 +39,7 @@ class NLA_HT_header(Header):
         sub = row.row(align=True)
         sub.popover(
             panel="NLA_PT_snapping",
-            icon='NONE',
-            text="Modes",
+            text="",
         )