Prepare for 56.1.0 release (#8202)

# Which issue does this PR close?

- Part of #7837

# Rationale for this change

Prepare for release
# What changes are included in this PR?

1. Changelog. Preview here:
https://github.com/alamb/arrow-rs/blob/alamb/prepare_for_56.1.0/CHANGELOG.md
2. Update version to `56.1.0`

Author: alamb