[4.x] Remove caching clause in FromParent resolver

[Kingdutch]

I think we can remove the explicit adding of the value to our cacheability information in

graphql/src/GraphQL/Resolver/ParentValue.php

Lines 19 to 21 in fa9764f

	if ($value instanceof CacheableDependencyInterface) {
	$context->addCacheableDependency($value);
	}

Since we already do so for all the results in our field resolver

graphql/src/Entity/Server.php

Lines 354 to 358 in fa9764f

	if ($result instanceof CacheableDependencyInterface) {
	$field->addCacheableDependency($result);
	}
	$context->addCacheableDependency($field);

This may seem like a small optimisation, but when looking at a relatively complex query addCacheableDependency was actually a place where the most time was spent and I theFromParent producer is actually on a hot path because a lot of fields use the parent's value to refine it further, so removing this unneeded function call may make a difference.

[Kingdutch]

If my understanding is correct the same would go for

graphql/src/GraphQL/Resolver/Value.php

Lines 35 to 37 in fa9764f

	if ($this->value instanceof CacheableDependencyInterface) {
	$context->addCacheableDependency($this->value);
	}