Metrics instrumentation httpx

[hectorhdzg]

What problem do you want to solve?

HTPP metrics: https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/semantic_conventions/http-metrics.md

Describe the solution you'd like

Add support for Metrics in httpx instrumentation

Describe alternatives you've considered

No response

Additional Context

No response

Would you like to implement a fix?

Yes

[hectorhdzg]

I would like to work on this, if someone can assign it to me it would be great, thanks.