What is the problem the feature request solves?

This issue is for planning the next major release of Comet, based on DataFusion 45.0.0 and Array 54.0.0.

There is a milestone for tracking issues that are being considered for this release:

https://github.com/apache/datafusion-comet/milestone/6

Issues & PRs targetted for this release:

• feat: Add fair unified memory pool #1369
• perf: improve performance of update metrics #1329
• Make cast from float/double to decimal compatible with Spark #1371 (to fix regression in TPC-H benchmark results)
• feat: Add unbounded memory pool #1386
• doc: update memory tuning guide #1394

Describe the potential solution

No response

Additional context

No response