Update datafusion <> homebrew instructions

[kevinjqliu]

Describe the bug

While looking at how datafusion publishes to homebrew, i came across the release instructions here and the release script here.

Looking at the homebrew-core repo, the datafusion library version looks to be automatically bumped, https://github.com/Homebrew/homebrew-core/pulls?q=is%3Apr+datafusion+is%3Aclosed

So we probably dont need those instructions and script above. Should we update and remove them?

To Reproduce

No response

Expected behavior

No response

Additional context

No response

[kevinjqliu]

cc @alamb i found this while looking into how datafusion was added to homebrew, as per datafusion-contrib/tpcgen-rs#121 (comment)

[alamb]

This is pretty amazing -- I don't really know who setup the homebrew stuff initially, so I don't know how much value there is in the instructions

[kevinjqliu]

cc @iajoiner who originally added the homebrew instructions in #3507
@alamb i tagged you to see if you ever ran these instructions during the release process.

Im pretty sure this is safe to remove; datafusion versions are automatically bumped in homebrew-core