Unpacking a nested object in Jsonnet to flatten the structure

Question

I have the following Jsonnet structure

{
  _config: {
    v: 3,
  },
  
  obj: {
    [std.char(97 + x)]: x
    for x in std.range(0, $._config.v - 1)
  }
}

which results in the following json

{
  "_config": {
    "v": 3
  },
  "obj": {
    "a": 0,
    "b": 1,
    "c": 2
  }
}

but I would like to like to unpack obj so the final object looks something like this

{
  "_config": {
    "v": 3
  },
  "a": 0,
  "b": 1,
  "c": 2
}

Is this possible to do?