feat(label): add syncLabels stub to Evolution Channel

Throws BadRequestException as syncLabels is only available
for Baileys (WhatsApp Web) connections.

Author: josuecocoman

src/api/integrations/channel/evolution/evolution.channel.service.ts

@@ -876,6 +876,9 @@ export class EvolutionStartupService extends ChannelStartupService {
   public async fetchLabels() {
     throw new BadRequestException('Method not available on Evolution Channel');
   }
+  public async syncLabels() {
+    throw new BadRequestException('Method not available on Evolution Channel');
+  }
   public async handleLabel() {
     throw new BadRequestException('Method not available on Evolution Channel');
   }