Can't concatenate charts that are loaded from json

[OleBialas]

What happened?

I want to store charts as JSON, exchange them with collaborators and then concatenate them.
However, attempting to concatenate the charts loaded from JSON/dict raises the following error:

I am trying to store charts as JSON, then load and concatenate them either horizontally or vertically.
Howeve, this raises the following error:

TypeError: Objects with 'config' attribute cannot be used within HConcatChart. Consider defining the config attribute in the HConcatChart object instead.

Here is a simple example to reproduce this behavior:

import altair as alt
from vega_datasets import data

cars = data.cars()

dct = alt.Chart(cars).mark_point().encode(
    x="Horsepower",
    y="Miles_per_Gallon"
).to_dict()

alt.hconcat(alt.Chart.from_dict(dct), alt.Chart.from_dict(dct))

It seems the issue is cause by the "config", "$schema" and "datasets" field in the dictionary.
The only workaround I found was to remove those keys and then pass the data argument to the concatenation function:

ct.pop('config')
dct.pop('$schema')
dct.pop('datasets')

alt.hconcat(alt.Chart.from_dict(dct), alt.Chart.from_dict(dct), data=cars)

However, this somewhat defeats the purpose because the shared Vega JSON is not self sufficient and depends on the availability of the data.
Is this behavior of hconcat/vconcat intended? I feel like this should be possible in Vega-Altair.

Thanks for this great package!

What would you like to happen instead?

No response

Which version of Altair are you using?

5.5.0