[Php81] Skip ArrayToFirstClassCallableRector on serialized callable array keys and Definition::setFactory()

[TomasVotruba]

Skip ArrayToFirstClassCallableRector when the [$value, 'method'] array is meant to stay an array rather than become a first class callable:

• array item keyed 'callback', 'factory', or 'validation_groups' — likely serialized to a callable string
• argument of Symfony's \Symfony\Component\DependencyInjection\Definition::setFactory(), which does not accept a first class callable

Context is marked during parsing via a new AttributeKey::IS_ARRAY_AS_STRING_CALLABLE set in ContextNodeVisitor, then checked in the rule.

Covered by 4 new skip fixtures.