Update CHANGELOG.MD with 1.23.0 release notes

[Christoph Bergmeister (bergmeister)]

PR Summary

Fixes #2042
In the past, we've always kept them in sync

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Change is not breaking
• Make sure all .cs, .ps1 and .psm1 files have the correct copyright header
• Make sure you've added a new test if existing tests do not effectively test the code changed and/or updated documentation
• This PR is ready to merge and is not Work in Progress.
  • If the PR is work in progress, please add the prefix WIP: to the beginning of the title and remove the prefix when the PR is ready.

[Andy Jordan (andyleejordan)]

I just plain forgot, and yeah, copy-pasting from the GitHub releases will probably be how we do this for the forseeable future.