Use Bukkit's isPrimaryThread check to set event sync status

[NonSwag]

Replaced the hardcoded true for asynchronous event handling with a dynamic !Bukkit.isPrimaryThread() check across all event constructors. This ensures events can be called synchronous or asynchronous based on the server thread context.

[NonSwag]

I only changed that behavior for async events but in theory the sync only events wouldn't cause issues when called from an async context
This change allows users for example to hide holograms from a sync context (which is basically always the case when working with bukkit events)