Convert array of objects, to object

I have a mongo db record like this

items: [
  0: {
    key: name,
    value: y
   },
  1: {
     key: module,
     value: z
   }
]

And per record my expected output is this

{
  name : y,
  module : z
}

What is the best mongo db aggregation i should apply to achieve this. I have tried few ways but i am unable to produce output. We can't use unwind otherwise it will break the relationship between name and module.

aggregate(
[{
    $project: {
        items: {
            $map: {
                input: "$items",
                "in": {
                    "k": "$$this.key",
                    "v": "$$this.value"
                }
            }

        }
    }
}, {
    $project: {
        items: {
            $arrayToObject: "$items"
        }
    }
}])

Test Code