[Tech Debt] Avoid create AgentPlan instance each time execute action.

[wenjin272]

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Description

Currently, each time execute an action task, ActionExecutionOperator will create a new runner context.

https://github.com/apache/flink-agents/blob/393b9ec946b9008aaf7c99dc0c036a51c80832b4/runtime/src/main/java/org/apache/flink/agents/runtime/operator/ActionExecutionOperator.java#L389

This behavior is to resolve the questions about action async execution, but will create new Resource instance each time execute an action and may cause connection leak risk.

The resources will cached in AgentPlan, so we could move the AgentPlan creation to open of operator, and wrap the same instance each time create new runner context.

Are you willing to submit a PR?

• [ ] I'm willing to submit a PR!