Release prep v6.0.0

[github-actions]

Automated release-prep through pdk-templates from commit cfbceb5.
Please verify before merging:

• last nightly run is green
• Changelog is readable and has no unlabeled pull requests
• Ensure the changelog version and metadata version match

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

GitHub Actions seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}