Fix Nightly Workflows and Update Release Policy

[radeusgd]

Pull Request Description

My previous PR that integrated the editions system (#1832) did introduce default editions tied to each engine version.

However I forgot to mention that after performing a release this edition number must be bumped and also that the nightly workflows should set this edition name to a nightly-specific name. Without this, editions from nightlies and releases could conflict leading to unexpected engine versions possibly being selected if multiple versions sharing the same edition name are installed.

This PR fixes that by updating the release policy, doing the overdue edition bump and adding automatic edition bumping to the nightly workflow.

Important Notes

Checklist

Please include the following checklist in your PR:

• The documentation has been updated if necessary.
• All code conforms to the Scala, Java, and Rust style guides.
• All documentation and configuration conforms to the markdown and YAML style guides.
• All code has been tested where possible.
  • A nightly build is running on staging to verify that the bumping code works correctly.