Implement ReduceNode for ScalarFnArray to avoid boxing

[robert3005]

fix #6436

[codspeed-hq]

Merging this PR will not alter performance

✅ 1135 untouched benchmarks
⏩ 1268 skipped benchmarks¹

---

_{Comparing rk/reducenode (47d5477) with develop (39425ae)²}

Footnotes

1. 1268 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on develop (dbe0ff5) during the generation of this report, so 39425ae was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[joseph-isaacs]

do we need this?

[robert3005]

I have a followup that maybe lets us remove this

[robert3005]

We do need this just like we need impl Array for Arc<dyn Array>

[gatesn]

When do we pull the trigger on Array vtable that lets us access &self within the Arc.

It should come with a lot of performance

[joseph-isaacs]

There is a horrible naming in the trait