Release DataFusion 15.0.0

[andygrove]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
I plan on creating DataFusion 15.0.0-rc1 on Friday 2nd December (4 weeks since the previous release).

Describe the solution you'd like

• Update version & generate changelog
• Cut RC and start vote
• Vote passes
• Release to crates.io
• Publish documentation

Describe alternatives you've considered

Additional context

[alamb]

@tustvold do you know of anything critical in arrow 30.0.0 #4818 for datafusion (aka should @andygrove hold the release for it)? I couldn't think of anything

[tustvold]

Nothing critical, just some nice to haves

[andygrove]

Thanks, I will go ahead with creating the RC for 16.0.0. This issue is for 15.0.0 so will close this. New issue is #4776