Use Valkyrie::ID<=>String equality
Use Valkyrie::ID<=>String equality

Valkyrie 2.1.0 overhauld ID equality as a feature-flag change, with the new
behavior to become default in 3.0.0. Turning it on preemtively for Hyrax will
save us and adopters a lot of trouble going forward.

samvera/hyrax,samvera/hyrax,samvera/hyrax,samvera/hyrax