🚸 Fix MKS LVGL UI temperature set interface (#22848)

Marlin/src/lcd/extui/mks_ui/draw_preHeat.cpp

         else if (uiCfg.extruderIndex == 0) {
           uiCfg.curTempType = TERN(HAS_HEATED_BED, 1, 0);
         }
+        lv_obj_del(btn_pla);
+        lv_obj_del(btn_abs);
       }
       else if (uiCfg.curTempType == 1) {
         uiCfg.extruderIndex = 0;
         uiCfg.curTempType = 0;
+        lv_obj_del(buttonAdd);
+        lv_obj_del(buttonDec);
         disp_add_dec();
         disp_ext_heart();
       }
+
       disp_temp_type();
       break;
-    case ID_P_STEP:
-      switch (uiCfg.stepHeat) {
-        case  1: uiCfg.stepHeat =  5; break;
-        case  5: uiCfg.stepHeat = 10; break;
-        case 10: uiCfg.stepHeat =  1; break;
-        default: break;
-      }
-      disp_step_heat();
-      break;
     case ID_P_OFF:
       if (uiCfg.curTempType == 0) {
         thermalManager.setTargetHotend(0, uiCfg.extruderIndex);

Marlin/src/lcd/extui/mks_ui/draw_ready_print.cpp

   lv_obj_set_style(det_info, &det_style);
   lv_label_set_text(det_info, "det:ok");
 }
+
 void disp_det_error() {
   det_style.text.color.full = 0xF800;
   lv_obj_set_style(det_info, &det_style);