[main] Update version to 51.0.0, add Changelog (#18551) (#18565)

## Which issue does this PR close?

- part of #17558
- port of #18551

## Rationale for this change

Let's update the version numbers!

## What changes are included in this PR?
- forward port the change from
#18551 to main

## Are these changes tested?
by CI

## Are there any user-facing changes?
New version

Author: alamb