utilities/Runtime/Vector2IntExtensions.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public static class Vector2IntExtensions
{
    public static Vector2Int Rotate(this Vector2Int v, float degrees)
    {
        float sin = Mathf.Sin(degrees * Mathf.Deg2Rad);
        float cos = Mathf.Cos(degrees * Mathf.Deg2Rad);
        float tx = v.x;
        float ty = v.y;
        float x = (cos * tx) - (sin * ty);
        float y = (sin * tx) + (cos * ty);
        return new Vector2Int(Mathf.RoundToInt(x), Mathf.RoundToInt(y));
    }
}