Empty-string JSON property names are dropped during request serialization

What are you generating using Kiota, clients or plugins?

API Client/SDK

In what context or format are you using Kiota?

Nuget tool

Client library/SDK language

Python

Describe the bug

When a request body contains an object definition, the Kiota Python client does not preserve properties whose name is an empty string ("").

The empty-string property name is valid JSON and is allowed by the OpenAPI schema. However, when the request is sent through the Kiota-generated Python client, the property is omitted from the serialized request body.

For example, the following request body:

{
  "properties": {
    "": {}
  }
}

is serialized by the Kiota Python client as:

{
  "properties": {}
}

Changing only the property name from "" to "a" causes it to be serialized correctly:

{
  "properties": {
    "a": {}
  }
}

This indicates that the empty property name is being treated differently during serialization.

Expected behavior

Kiota Python should preserve valid empty-string property names when serializing objects.

How to reproduce

1. Generate a Python client from the provided OpenAPI description.
2. Create and send a request to POST /jobExecutions with body {"properties":{"":{}}}
3. Capture the outgoing HTTP request

I sent the request using

await client.job_executions.post(body=JsonParseNodeFactory().get_root_parse_node(
            "application/json",
            '{"properties": {"": {}}}'.encode()
            ).get_object_value(JobConfig))

The captured request body is {"properties": {}}

Open API description file

https://github.com/WebFuzzing/Dataset/blob/master/openapi-swagger/spring-batch-rest.json

I suspect this would work with any description that allows empty string keys in a JSON body

Kiota Version

1.35.0

Latest Kiota version known to work for scenario above?(Not required)

No response

Known Workarounds

No response

Configuration

Fedora 43

Debug output

</details>


### Other information

_No response_

Generate a Python client from the referenced spring-batch-rest.json description and reproduce POST /jobExecutions with JsonParseNodeFactory and JobConfig using {"properties":{"":{}}}. Trace the request serialization path and compare it with the working "a" property case; done means the captured request preserves the empty-string property name.