Simple 0 dependency Event Bus for Unity C#

EventManager.cs

using System;

public static class EventManager<T>
{
    private static event Action<T> Event;

    public static void AddListener(Action<T> handler) => Event += handler;

    public static void RemoveListener(Action<T> handler) => Event -= handler;
    
    public static void RemoveAllListeners() => Event = null;

    public static void Invoke(T arg) => Event?.Invoke(arg);
}