fix(telemetry): added latest semantic conventions as span attributes for langfuse

[poshinchen]

Description

Currently Langfuse do not read some of the latest semantic conventions via event attributes, instead they read from the span attributes. Therefore we have to add those event attributes into span attributes when users are using langfuse.

Related Issues

N/A

Documentation PR

N/A

Type of Change

Bug fix

Testing

How have you tested the change? Verify that the changes do not break functionality or introduce warnings in consuming repositories: agents-docs, agents-tools, agents-cli

• I ran hatch run prepare

Checklist

• I have read the CONTRIBUTING document
• I have added any necessary tests that prove my fix is effective or my feature works
• I have updated the documentation accordingly
• I have added an appropriate example to the documentation to outline the feature, or no new docs are needed
• My changes generate no new warnings
• Any dependent changes have been merged and published

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[github-actions]

Assessment: Request Changes

Good approach to handling Langfuse's span attribute requirements. The implementation correctly adds event attributes to span attributes when using Langfuse as the OTLP endpoint.

Review Summary

• Code Duplication: One instance of duplicated Langfuse detection logic should use the new self.is_langfuse instance variable for consistency
• Refactoring: The removal of the _set_attributes wrapper method in favor of direct span.set_attributes() calls is a nice simplification
• Testing: Good test coverage for both Langfuse and non-Langfuse scenarios

Once the duplicated check is replaced with self.is_langfuse, this is ready to merge.