[bug] [improvement] Dual specialization is available to all WoW clients

[Myrroddin]

This is a duplicate of issue #14 on Curseforge. All WoW clients, including vanilla Classic Era, now support at least two talent builds per character.

Furthermore, Anniversary is now TBC, and is no longer a Classic Era variant of the game.

v.1.29.1 of LibDualSpec-1.0 has not been updated with this new information, and still exits in vanilla Classic Era.