Unity NavMesh pathfinding using Job System

I'm trying to write a system where I can run each enemy's NavMesh pathfinding in parallel, using Job System.

The problem I'm having is that I can't pass the NavMesh agent argument as it's a reference type.

InvalidOperationException: PathfindJob.agent is not a value type. Job structs may not contain any reference types.

I'm probably approaching this problem in a completely wrong way, but this is all I've come up with.

Here's the current Enemy code

using System.ComponentModel;
using Managers;
using Unity.Collections;
using Unity.Jobs;
using UnityEngine;
using UnityEngine.AI;
using UnityEngine.Jobs;

namespace Characters
{
    [RequireComponent(typeof(Rigidbody))]
    public class Enemy : MonoBehaviour
    {
        [Header("Stats"), SerializeField] private int _health = 100;
        [SerializeField] private int _damage = 20;
        [SerializeField] private float _aggroRadius = 10f;

        private Rigidbody _body;
        private NavMeshAgent _agent;
        private Transform _target;

        private void Awake()
        {
            _body = GetComponent<Rigidbody>();
            _agent = GetComponent<NavMeshAgent>();
            _target = PlayerManager.GetInstance().GetPlayer();
        }

        private void OnDrawGizmosSelected()
        {
            Gizmos.color = Color.blue;
            Gizmos.DrawWireSphere(transform.position, _aggroRadius);
        }
    }

    public struct PathfindJob : IJobParallelForTransform
    {
        public Vector3 TargetPosition;
        public NavMeshAgent Agent;
        public float AggroRadius;

        public void Execute(int index, TransformAccess transform)
        {
            var distance = Vector3.Distance(TargetPosition, transform.position);

            if (distance < AggroRadius)
                Agent.SetDestination(TargetPosition);
        }    
    }
}

I'm scheduling the job from the GameManager class.