Request for Reviewers for Spark Runner Improvements

[LDesire]

Hi Beam Dev Community, I've made some updates to Spark Runner in Apache Beam. 
The updates are in these PRs: - #32546 : optimized to skip filter operation 
when there is only one output - #32610 : Change to use partitioner in 
GroupNonMergingWindowsFunctions#groupByKeyInGlobalWindow Please review if you 
know the Beam Spark Runner or someone who might be interested. Thank you for 
your time and contributions! Best regards