Release notes for `0.94.0`

[devyn]

Please add your new features and breaking changes to the release notes by opening PRs against the release-notes-0.94.0 branch.

TODO

• [x] look at interesting contributions
• [x] write all the sections
• [x] order the sections by interest
• [x] add the breaking changes
• [x] detail the breaking changes
• [x] add the full changelog
• [x] complete all the TODOs inside the release note
• [x] ... (PRs that need to land before the release, e.g. deprecations or removals)