perf: Subsplitting large chunks causes some regression for vortex-compact for some benchmarks

[AdamGS]

Seems like #8400 causes some queries over vortex-compact significant regressions, while most others seem to be better or about the same.

The affected queries include:

• Clickbench Q2, Q3, Q7, Q9, Q10, Q11, Q19, Q25, Q29,
• TPC-DS Q19, Q33, Q34, Q46, Q50, Q56, Q68, Q79, Q88, Q96

This regression affects both DuckDB and DataFusion, but not always both. It also improves a bunch of queries over vortex-compact, for example TPC-DS Q92.

[myrrc]

Clickbench Q7 is a 2x regression on regular vortex.