Fixes for deprecation notices.

Ted Cooperrequested to merge
issue/cas_server-3621896:2.1.x-3621896-deprecation-fixes into 2.1.x
  • Future proof ConstraintValidatorInterface::validate() with void typehint.
  • Fix drupal.entityStoragePropertyAssignment in test.
  • Add PHPUnit 12 Attributes. Not removing DocBlock to keep BC.

Merge request reports