Remove now unused locals

Author: jozkee

src/Libraries/Microsoft.Extensions.AI.OpenAI/OpenAIChatClient.cs

@@ -246,11 +246,9 @@ private static async IAsyncEnumerable<ChatResponseUpdate> FromOpenAIStreamingCha
         Dictionary<int, FunctionCallInfo>? functionCallInfos = null;
         ChatRole? streamedRole = null;
         ChatFinishReason? finishReason = null;
-        StringBuilder? refusal = null;
         string? responseId = null;
         DateTimeOffset? createdAt = null;
         string? modelId = null;
-        string? fingerprint = null;
 
         // Process each update as it arrives
         await foreach (StreamingChatCompletionUpdate update in updates.WithCancellation(cancellationToken).ConfigureAwait(false))
@@ -261,7 +259,6 @@ private static async IAsyncEnumerable<ChatResponseUpdate> FromOpenAIStreamingCha
             responseId ??= update.CompletionId;
             createdAt ??= update.CreatedAt;
             modelId ??= update.Model;
-            fingerprint ??= update.SystemFingerprint;
 
             // Create the response content object.
             ChatResponseUpdate responseUpdate = new()
@@ -287,12 +284,6 @@ private static async IAsyncEnumerable<ChatResponseUpdate> FromOpenAIStreamingCha
                 }
             }
 
-            // Transfer over refusal updates.
-            if (update.RefusalUpdate is not null)
-            {
-                _ = (refusal ??= new()).Append(update.RefusalUpdate);
-            }
-
             // Transfer over tool call updates.
             if (update.ToolCallUpdates is { Count: > 0 } toolCallUpdates)
             {