[various] Update Pigeon for task queue changes (#8654)
Picks up the changes to task queue code generation in Pigeon 24.2.0, so that calls to different background methods will be serialized within the whole group, rather than by individual method, as that was how they were intended to work in the first place (and was how the plugins worked when delegation to a background thread was done manually with the plugin, before adopting task queues)