.Net: Bug - package Microsoft.SemanticKernel.Agents.OpenAI file_search tool call no longer works past nuget v1.24.1-alpha

[Mano1192]

Describe the bug The file_search tool call works as expected in v1.24.1-alpha, as you update all SK packages to 1.29 and equivalent latest packages this feature breaks. The last known latest versions of all packages where file_search tool calling works:

To Reproduce Steps to reproduce the behavior:

1. Setup up test with the packages listed above (this is the working state)
2. Update any of the packages up 1 version
3. Create an openaiassistantagent and attach a file
4. Search contents within this file and the following exception is raised

   System.NullReferenceException: Object reference not set to an instance of an object.
   at OpenAI.Assistants.RunStepDetailsUpdate.get_FunctionName()
   at Microsoft.SemanticKernel.Agents.OpenAI.Internal.AssistantThreadActions.InvokeStreamingAsync(OpenAIAssistantAgent agent, AssistantClient client, String threadId, IList`1 messages, OpenAIAssistantInvocationOptions invocationOptions, ILogger logger, Kernel kernel, KernelArguments arguments, CancellationToken cancellationToken)+MoveNext()
   at Microsoft.SemanticKernel.Agents.OpenAI.Internal.AssistantThreadActions.InvokeStreamingAsync(OpenAIAssistantAgent agent, AssistantClient client, String threadId, IList`1 messages, OpenAIAssistantInvocationOptions invocationOptions, ILogger logger, Kernel kernel, KernelArguments arguments, CancellationToken cancellationToken)+MoveNext()
   at Microsoft.SemanticKernel.Agents.OpenAI.Internal.AssistantThreadActions.InvokeStreamingAsync(OpenAIAssistantAgent agent, AssistantClient client, String threadId, IList`1 messages, OpenAIAssistantInvocationOptions invocationOptions, ILogger logger, Kernel kernel, KernelArguments arguments, CancellationToken cancellationToken)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult()

Notes

• These were the latest packages that work together where we could identify was the last working state of the file_search tool call.