Make overblog/graphiql-bundle optional

[charly-ffss]

Fixes #271
Refs #245

This makes overblog/graphiql-bundle truly optional, as documented.
It allows installing graphqlite-bundle on Symfony 8 without requiring GraphiQL.

[andrew-demb]

Is it necessary to drop GraphiQL-related classes from the DI container in case of a non-existing dependency?

graphqlite-bundle/src/DependencyInjection/OverblogGraphiQLEndpointWiringPass.php

Lines 14 to 20 in ecc9dbc

	public function process(ContainerBuilder $container): void
	{
	$endPointDefinition = new Definition(EndpointResolver::class);
	$endPointDefinition->addArgument(new Reference('request_stack'));
	$container->setDefinition('overblog_graphiql.controller.graphql.endpoint', $endPointDefinition);
	}

[charly-ffss]

Is it necessary to drop GraphiQL-related classes from the DI container in case of a non-existing dependency?

graphqlite-bundle/src/DependencyInjection/OverblogGraphiQLEndpointWiringPass.php

Lines 14 to 20 in ecc9dbc

	public function process(ContainerBuilder $container): void
	{
	$endPointDefinition = new Definition(EndpointResolver::class);
	$endPointDefinition->addArgument(new Reference('request_stack'));
	$container->setDefinition('overblog_graphiql.controller.graphql.endpoint', $endPointDefinition);
	}

Good point.

Currently, the compiler pass does not reference any Overblog GraphiQL classes directly, so declaring the service alone should not crash even if the bundle is not installed.

That said, now that overblog/graphiql-bundle is optional, it would probably be safer to guard this wiring (e.g. checking bundle presence or class existence) to avoid registering GraphiQL-related services when the dependency is not installed.

I didn’t include this change in the PR since the goal here was limited to making the dependency optional at the Composer level.

[andrew-demb]

OK, let's merge as is.

Thank you @charly-ffss