feat(qwen-agent): add instrumentation for Qwen-Agent

[sipercai]

Description

This PR adds loongsuite-instrumentation-qwen-agent: OpenTelemetry instrumentation for Qwen-Agent using ExtendedTelemetryHandler from opentelemetry-util-genai. It emits GenAI semantic-convention traces for agent runs, LLM calls, ReAct steps, and tool execution (invoke_agent, chat, react step, execute_tool), registers an opentelemetry_instrumentor entry point, and includes unit tests plus VCR-based integration tests.

Fixes #11

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

pip install -e ".[test]" under instrumentation-loongsuite/loongsuite-instrumentation-qwen-agent, then pytest on that package’s tests/
From repo root: tox -c tox-loongsuite.ini -e py312-test-loongsuite-instrumentation-qwen-agent-oldest, py312-test-loongsuite-instrumentation-qwen-agent-latest, lint-loongsuite-instrumentation-qwen-agent

• Test A

Does This PR Require a Core Repo Change?

• Yes. - Link to PR:
• No.

Checklist:

See contributing.md for styleguide, changelog guidelines, and more.

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated