Not at all. The domain layer is old good PHP, but you can use Symfony to implement all sort of things at the infrastructure level. The key here is to apply the Dependency Inversion Principle.
Okay. As you probably guessed I don't know anything about DDD but I'll try to find some time to read about it.
I would strongly recommend two of the books mentioned here as a good starting points: DDD in PHP and The Clean Architecture.
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