Schema can get cached without GraphQL compose contributions

Problem/Motivation

We have a production site where the schema can sometimes be cached in an incomplete state,

This results in 404s on the Front-end application, and a Drupal cache rebuild is required to fix, same issue as https://www.drupal.org/project/graphql/issues/3477239 🐛 GraphQL query stops working - seems cache issue Needs work I believe.

Since it seems to be the graphql compose portion only, we should look into this as to how we get the cache and how it can fail. I believe it's around this stack:

GraphQLComposeSchemaTypeManager.php:234, Drupal\graphql_compose\Plugin\GraphQLComposeSchemaTypeManager->printTypes()
AlterSchemaSubscriber.php:60, Drupal\graphql_compose\EventSubscriber\AlterSchemaSubscriber->alterSchema()
ContainerAwareEventDispatcher.php:111, call_user_func:{/var/www/html/docroot/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php:111}()
ContainerAwareEventDispatcher.php:111, Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch()
AlterableComposableSchema.php:129, Drupal\graphql\Plugin\GraphQL\Schema\AlterableComposableSchema->getSchemaDocument()

Steps to reproduce

Not reproduceable, happens intermittently on cache clear

Proposed resolution

Prevent code execution if schema generation fails.

Remaining tasks

User interface changes

API changes

Data model changes