`OllamaChatClient` doesn't check for status code before deserializing.

[eiriktsarpalis]

Description

Per the title, the client currently doesn't check response status codes before deserializing in both the non-streaming

extensions/src/Libraries/Microsoft.Extensions.AI.Ollama/OllamaChatClient.cs

Lines 90 to 97 in fc84cf9

	var response = (await httpResponse.Content.ReadFromJsonAsync(
	JsonContext.Default.OllamaChatResponse,
	cancellationToken).ConfigureAwait(false))!;
	if (!string.IsNullOrEmpty(response.Error))
	{
	throw new InvalidOperationException($"Ollama error: {response.Error}");
	}

and streaming implementations

extensions/src/Libraries/Microsoft.Extensions.AI.Ollama/OllamaChatClient.cs

Lines 119 to 126 in fc84cf9

	using var httpResponse = await _httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken).ConfigureAwait(false);
	using var httpResponseStream = await httpResponse.Content
	#if NET
	.ReadAsStreamAsync(cancellationToken)
	#else
	.ReadAsStreamAsync()
	#endif
	.ConfigureAwait(false);

In practice, this results in one single empty chat update being returned in cases where, for example, Ollama returns a 404 response. We should fix this and ensure that OllamaSharp doesn't suffer from the same issue.

Reproduction Steps

N/A

Expected behavior

Should throw an exception when non 20x responses are being produced.

Actual behavior

Does not throw an exception when non-20x responses are being produced.

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response