feat(crewai): Enable Tracing Support For CrewAI AgentAction

[ialisaleh]

This PR adds tracing support for the CrewAI AgentAction.

Example Trace

Closes #2037

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Note

Adds tracing for CrewAI AgentAction with input/output serialization and updates tests to validate new spans.

• Instrumentation:
  • Wraps crewai.agents.crew_agent_executor.CrewAgentExecutor._handle_agent_action with _AgentActionWrapper; tracks original and restores on uninstrument.
• Wrappers:
  • New _AgentActionWrapper creates UNKNOWN spans for AgentAction handling; records serialized inputs (AgentAction) and outputs (AgentFinish) using OpenInferenceMimeTypeValues.JSON and flattens attributes.
  • Adds _serialize_agent_object (supports dataclass and legacy objects) and imports asdict/is_dataclass.
  • Extends semconv imports to include OpenInferenceMimeTypeValues.
• Tests:
  • Update span expectations from 5 to 7 (add 2 AgentAction spans); assert counts for TOOL and UNKNOWN kinds and keep existing crew/agent/flow validations.

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