System.Text.Json doesn't deserialize IDictionary<string, string> if get only property

[componentspace]

In the following code Newtonsoft.Json correctly deserializes but System.Text.Json doesn't with the dictionary being empty. If the IDictionary<string, string> property has a setter, the deserialization works. However, I don't control the class that requires serialization/deserialization and it includes IDictionary<string, string> properties with getters only.

`
using Newtonsoft.Json;
using System.Collections.Generic;
using System.Text.Json;

namespace TestConsoleApp
{
class Test
{
public IDictionary<string, string> Items { get; } = new Dictionary<string, string>();
}

class Program
{
    static void Main(string[] args)
    {
        var test = new Test();
        test.Items["a"] = "1";
        test.Items["b"] = "2";

        var json = System.Text.Json.JsonSerializer.Serialize(test);

        // Dictionary is empty.
        var test2 = System.Text.Json.JsonSerializer.Deserialize<Test>(json);

        // Correctly deserialized.
        var test3 = JsonConvert.DeserializeObject<Test>(json);
    }
}

}

`

[ghost]

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[Symbai]

#30258
#30688

[layomia]

Closing as dup of #30258