[8.19] (backport #285) Update CHANGELOG.md for 8.18.0

[mergify]

---

This is an automatic backport of pull request #285 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of cfb20a7 has failed:

On branch mergify/bp/8.19/pr-285
Your branch is up to date with 'origin/8.19'.

You are currently cherry-picking commit cfb20a7.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   CHANGELOG.md

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[andsel]

[Minor] Added space

[elasticmachine]

💔 Build Failed

• Buildkite Build
• Commit: 4712da3

Failed CI Steps

• Unit test for 8.17.6-SNAPSHOT, snapshot: true
• Integration test for 8.17.6-SNAPSHOT, snapshot: true

History

• 💔 Build #536 failed 5816fcd

cc @andsel

[jsvd]

LGTM