Python: Add agent invocation spans

[TaoChenOSU]

Motivation and Context

Address feature request: #10174

Description

This pull request introduces a new decorator for tracing agent invocations and applies it to various methods in the ChatCompletionAgent and OpenAIAssistantAgent classes. Additionally, it includes new unit tests to ensure the decorator is correctly applied and functions as expected.

Key Changes:

Decorator Implementation:

• Added a new trace_agent_invocation decorator in python/semantic_kernel/utils/telemetry/agent_diagnostics/decorators.py to trace agent invocations using OpenTelemetry.

Decorator Application:

• Applied the trace_agent_invocation decorator to the invoke and invoke_stream methods in ChatCompletionAgent (python/semantic_kernel/agents/chat_completion/chat_completion_agent.py). [1] [2] [3]
• Applied the trace_agent_invocation decorator to the invoke and invoke_stream methods in OpenAIAssistantAgent (python/semantic_kernel/agents/open_ai/open_ai_assistant_base.py). [1] [2] [3]

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
semantic_kernel/agents/open_ai
open_ai_assistant_base.py	483	7	99%	256, 342–343, 754, 922, 996, 1060
TOTAL	16731	1777	89%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3010	4 💤	0 ❌	0 🔥	1m 12s ⏱️

[esttenorio]

should there be a readme or a demo mentioning/explaining the use of the new decorator?