🩹 Fix DGUS_PREHEAT_UI enable with DGUS_LCD_CLASSIC (#24066)

Marlin/src/inc/Conditionals_post.h

@@ -3295,7 +3295,7 @@
   #define HAS_TEMPERATURE 1
 #endif
 
-#if HAS_TEMPERATURE && EITHER(HAS_MARLINUI_MENU, HAS_DWIN_E3V2)
+#if HAS_TEMPERATURE && ANY(HAS_MARLINUI_MENU, HAS_DWIN_E3V2, HAS_DGUS_LCD_CLASSIC)
   #ifdef PREHEAT_6_LABEL
     #define PREHEAT_COUNT 6
   #elif defined(PREHEAT_5_LABEL)

Marlin/src/lcd/extui/dgus/DGUSScreenHandler.cpp

@@ -629,8 +629,10 @@ void DGUSScreenHandler::HandleHeaterControl(DGUS_VP_Variable &var, void *val_ptr
       default:
       switch (var.VP) {
         default: return;
-        case VP_E0_BED_PREHEAT: TERN_(HAS_HOTEND,       ui.preheat_all(0)); break;
-        case VP_E1_BED_PREHEAT: TERN_(HAS_MULTI_HOTEND, ui.preheat_all(1)); break;
+        case VP_E0_BED_PREHEAT: TERN_(HAS_HOTEND, ui.preheat_all(0)); break;
+        #if DISABLED(DGUS_LCD_UI_HIPRECY) && HAS_MULTI_HOTEND
+          case VP_E1_BED_PREHEAT: ui.preheat_all(1); break;
+        #endif
       }
       case 7: break; // Custom preheat
       case 9: thermalManager.cooldown(); break; // Cool down