fix: update delete button behavior in TreeCategoryHeader and TeamsList

- Removed unnecessary canDelete prop from TreeCategoryHeader's delete button condition.
- Added disabled state to the delete button based on canDelete logic.
- Updated canDelete prop in TeamsList to reflect whether the direction has members.

components/admin/teams/teams-list.tsx

@@ -50,7 +50,7 @@ export function TeamsList({
               itemLabel="équipe"
               showSeparator={index > 0}
               onDelete={() => onDeleteDirection(direction)}
-              canDelete={true}
+              canDelete={!getDirectionStats(direction).hasMembers}
               isDirection={true}
               directionStats={getDirectionStats(direction)}
             />