Add return typehint to \Drupal\Core\DependencyInjection\DeprecatedServicePropertyTrait::__get()

Added review feedback regarding returning null.

Discussed throwing an exception with @mstrelan and agreed that would be a behaviour change that would be out of scope for this issue.

Discussed this with @kim.pepper and we agreed this has to return NULL to maintain existing behaviour rather than throwing an exception.

Makes sense, we probably want to do this in all traits to avoid this problem?

Committed and pushed 63f216f3891 to 11.x and 0bc0cb23a12 to 11.1.x. Thanks!

quietone → closed merge request !9817

Automatically closed - issue fixed for 2 weeks with no activity.