Add XCom Push Support in Deferred for KPO

[jscheffl]

With PR #64068 assuming it is possible to make this into Airflow 3.2.0 it is possible to push XCom directly from triggerer.

Except callbacks this would resolve the need to return to a worker to complete a task directly from triggerer. This PR builds on top of #64068 and applies the feature to KPO:

• XComs are retrieved from pushed from triggerer
• Except if Airflow is not 3.2.0 - then the current approach is used
• Except if a callback is defined - then the current approach is used

Note that CI will most probably fail until PR #64068 is not merged.

• closes: Allow direct queueing from triggerer #63489
• related: Add XCom Push Support for Triggerer #64068

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Claude Opus 4.6

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