Hi all, I'd like to confirm whether the project would accept a small patch
related to parallel CustomScan handling in the MPP layer. While integrating a parallel-aware CustomScan in a downstream extension, I noticed that the Cloudberry-specific MPP parallel walkers don't dispatch T_CustomScanState, even though the equivalent PG walkers in the same file already do. As a result, a parallel-aware CustomScan whose children sit under custom_ps ends up with no DSM state initialised on the worker side under Gather Motion. The impact is limited to extensions that want to enable parallel-aware CustomScan and currently can't.
