[FEATURE] Emit OTel following the latest Gen Ai semantic convention

[dbschmigelski]

Problem Statement

Strands emits OTel following Semantic Conventions 1.36.0. Because the gen ai convention is so new it is subject to breaking changes which did occur in the newest 1.37.0

Proposed Solution

Following the official warning on https://opentelemetry.io/docs/specs/semconv/gen-ai/, we should

[!Warning]

Existing GenAI instrumentations that are using [v1.36.0 of this document](https://github.com/open-telemetry/semantic-conventions/blob/v1.36.0/docs/gen-ai/README.md) (or prior):

- SHOULD NOT change the version of the GenAI conventions that they emit by default. Conventions include, but are not limited to, attributes, metric, span and event names, span kind and unit of measure.
- SHOULD introduce an environment variable OTEL_SEMCONV_STABILITY_OPT_IN as a comma-separated list of category-specific values. The list of values includes:
  - gen_ai_latest_experimental - emit the latest experimental version of GenAI conventions (supported by the instrumentation) and do not emit the old one (v1.36.0 or prior).
  - The default behavior is to continue emitting whatever version of the GenAI conventions the instrumentation was emitting (1.36.0 or prior).
This transition plan will be updated to include stable version before the GenAI conventions are marked as stable.

Use Case

Sync Strands Gen AI convention with the latest standard.

Alternatives Solutions

No response

Additional Context

No response