[FLINK-39801][table] Skip serializing empty partition/order keys for PTF table args

[raminqaf]

What is the purpose of the change

TABLE_ARG_CALL nodes always wrote partitionKeys, orderKeys, and orderDirections into the compiled plan JSON, even when empty. Table arguments without PARTITION BY and ORDER BYare common, so these empty arrays bloat the plan for no benefit. This change omits the arrays when empty, matching how serializeCall already skips empty operands.

Brief change log

• RexNodeJsonSerializer skips partitionKeys / orderKeys / orderDirections when they are empty.
• RexNodeJsonDeserializer treats the three fields as optional and defaults them to empty arrays when absent, so plans written by older versions still load.
• Regenerated the affected PTF / TO_CHANGELOG / FROM_CHANGELOG restore plan files to drop the now-omitted arrays.

Verifying this change

This change is already covered by existing tests, such as the stream-exec-process-table-function, TO_CHANGELOG, and FROM_CHANGELOG restore tests. They load the regenerated plans through the deserializer and pass. The deserializer change keeps older plans that still contain the empty arrays loadable, preserving backward compatibility.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: yes. The compiled-plan JSON format changes, but it is backward compatible: the deserializer reads plans both with and without the arrays.
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? not applicable

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Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

[flinkbot]

CI report:

• f2a3f98 Azure: SUCCESS

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[snuyanzin]

Why is it called deserializeArrayOrEmpty however returns a list?
can we make it returning array in order to encapsulate

.mapToInt(Integer::intValue)
                        .toArray();

and probably just call it deserializeArray

[raminqaf]

Renamed to deserializeListOrEmpty and used it for objects like SortOrder. Introduced a new method called deserializeToIntArray that uses deserializeListOrEmpty.

[snuyanzin]

LGTM
Thanks for addressing feedback

let's wait for CI