Add support for Anthropic Beta Streaming API with OpenTelemetry

[floriafz23]

Resolves #649

[floriafz23]

@evalstate Is this PR ready for merge?

[evalstate]

I can't make it work locally with streaming / crashing so put to one side momentarily. I assume you are getting OTEL traces with 0.4.43 and this patch?

[floriafz23]

I can't make it work locally with streaming / crashing so put to one side momentarily. I assume you are getting OTEL traces with 0.4.43 and this patch?

Yup, I'm able to get OTEL traces with this. Also, the versions I gave before were wrong, I think. These are the versions I'm using:

opentelemetry-api                          1.39.0
opentelemetry-distro                       0.60b0
opentelemetry-exporter-otlp                1.39.0
opentelemetry-exporter-otlp-proto-common   1.39.0
opentelemetry-exporter-otlp-proto-grpc     1.39.0
opentelemetry-exporter-otlp-proto-http     1.39.0
opentelemetry-exporter-prometheus          0.60b0
opentelemetry-instrumentation              0.60b0
opentelemetry-instrumentation-anthropic    0.49.6
opentelemetry-instrumentation-asyncio      0.60b0
opentelemetry-instrumentation-google-genai 0.4b0
opentelemetry-instrumentation-httpx        0.60b0
opentelemetry-instrumentation-logging      0.60b0
opentelemetry-instrumentation-mcp          0.49.6
opentelemetry-instrumentation-openai       0.49.6
opentelemetry-instrumentation-urllib       0.60b0
opentelemetry-proto                        1.39.0
opentelemetry-sdk                          1.39.0
opentelemetry-semantic-conventions         0.60b0
opentelemetry-semantic-conventions-ai      0.4.13
opentelemetry-util-genai                   0.2b0
opentelemetry-util-http                    0.60b0

The patch doesn't work with some newer opentelemetry-instrumentation-anthropic versions.

[evalstate]

Thank you - I'll take another look fairly soon then (as it's been frustrating me for a while) - it's just that the failure mode is pretty horrible, and the OTEL plugins seem super-sensitive to cross-version issues.