Conditionally compile API user services to save 4.3KB flash (follow-up to #9262) (#9451)

esphome/core/component_iterator.cpp

@@ -4,6 +4,8 @@
 
 #ifdef USE_API
 #include "esphome/components/api/api_server.h"
+#endif
+#ifdef USE_API_SERVICES
 #include "esphome/components/api/user_services.h"
 #endif
 
@@ -148,7 +150,7 @@ void ComponentIterator::advance() {
       }
       break;
 #endif
-#ifdef USE_API
+#ifdef USE_API_SERVICES
     case IteratorState ::SERVICE:
       if (this->at_ >= api::global_api_server->get_user_services().size()) {
         advance_platform = true;
@@ -383,7 +385,7 @@ void ComponentIterator::advance() {
 }
 bool ComponentIterator::on_end() { return true; }
 bool ComponentIterator::on_begin() { return true; }
-#ifdef USE_API
+#ifdef USE_API_SERVICES
 bool ComponentIterator::on_service(api::UserServiceDescriptor *service) { return true; }
 #endif
 #ifdef USE_CAMERA