Fix connection port field validation (#68382)

[Alwaysgaurav1]

This PR implements error propagation for variable write (set) and delete (delete) operations inside the Task SDK. Previously, if the API server rejected these operations, the returned ErrorResponse was ignored by the task runner, causing the task to report success despite a backend failure.

closes: #68537

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[boring-cyborg]

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[Alwaysgaurav1]

Hi maintainers! 👋 This is my first contribution to Apache Airflow. Could someone please approve the CI workflow runs so the tests can execute?

Also tagging @ashb since you commented on the original issue #68382 with guidance on the port validation approach. This PR implements validation (1-65535) across all entry points: core model, REST API, Task SDK, connection test model, and CLI — with a shared validate_port() helper and 19 test cases.

Thank you! 🙏

[pierrejeambrun]

Thanks @Alwaysgaurav1 for the PR.

Unfortunately there is already #68777 opened for this and closer to being merged.

Closing in favor of it you can take a look at the reviews there a bunch also applies for yours.