Prepare version 31

[andygrove]

Which issue does this PR close?

N/A

Rationale for this change

Prepare for 31 release

What changes are included in this PR?

• Use lastest DataFusion from main branch for now, will switch to 31.0.0 when released

Are there any user-facing changes?

[andygrove]

Closed in favor of https://github.com/apache/arrow-datafusion-python/pull/491