Missing Dataloaders in AOT/GraalVM Native

[MrOstling]

When we updated to 10.4.0 we were unable to get dataloaders for apps that use AOT or GraalVM.

We tracked down the issue to the new dataloader reload feature changing a class to an interface.

Before 10.4.0:

AOT generated
public static BeanDefinition getDgsDataLoaderProviderBeanDefinition() {
RootBeanDefinition beanDefinition = new RootBeanDefinition(DgsDataLoaderProvider.class);
beanDefinition.setInitMethodNames("findDataLoaders$graphql_dgs");
beanDefinition.setFactoryBeanName("com.netflix.graphql.dgs.springgraphql.autoconfig.DgsSpringGraphQLAutoConfiguration");
beanDefinition.setInstanceSupplier(getDgsDataLoaderProviderInstanceSupplier());
return beanDefinition;
}

After 10.4.0:

AOT generated
public static BeanDefinition getDgsDataLoaderProviderBeanDefinition() {
RootBeanDefinition beanDefinition = new RootBeanDefinition(DgsDataLoaderProvider.class);
beanDefinition.setFactoryBeanName("com.netflix.graphql.dgs.springgraphql.autoconfig.DgsSpringGraphQLAutoConfiguration");
beanDefinition.setInstanceSupplier(getDgsDataLoaderProviderInstanceSupplier());
return beanDefinition;
}

The missing init method causes the dataloader registry not to get populated.

Proposed fix:
Change DgsDataLoaderProvider to DefaultDgsDataLoaderProvider when creating the bean here. This allows AOT to detect the @PostConstruct annotation properly in DefaultDgsDataLoaderProvider. This is analogous to the changes made in this PR.