Remove RefereeLevel.ordering now inherits_from covers the same need

A separate manually-kept number for "which tier is higher" is
redundant now that the inheritance chain already expresses it, and
risked drifting out of sync with it. Levels list/sort by name only.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ECGMEwrc2k4D8VQuwjstj9

teams/admin.py

@@ -72,11 +72,11 @@ class StaffAssignmentAdmin(admin.ModelAdmin):
 
 @admin.register(RefereeLevel)
 class RefereeLevelAdmin(admin.ModelAdmin):
-    list_display = ["name", "club", "ordering", "inherits_from", "team_list"]
+    list_display = ["name", "club", "inherits_from", "team_list"]
     list_filter = ["club"]
     search_fields = ["name"]
     autocomplete_fields = ["teams", "inherits_from"]
-    ordering = ["club", "ordering", "name"]
+    ordering = ["club", "name"]
 
     @admin.display(description=_("teams"))
     def team_list(self, obj):