change dependency schema in porter

[VinozzZ]

What does this change

This PR updates the dependency schema to prepare for the advanced dependency feature
https://github.com/getporter/proposals/blob/main/pep/003-dependency-namespaces-and-labels.md#porteryaml

What issue does it fix

Notes for the reviewer

We want to make this change before v1 release so that users don't have to do another schema update immediately after v1

Checklist

• Did you write tests?
• Did you write documentation?
• Did you change porter.yaml or a storage document record? Update the corresponding schema file.
• If this is your first pull request, please add your name to the bottom of our Contributors list. Thank you for making Porter better! 🙇‍♀️

Reviewer Checklist

• Comment with /azp run test-porter-release if a magefile or build script was modified
• Comment with /azp run porter-integration if it's a non-trivial PR

[carolynvs]

Holding off on merging until the integration tests are fixed in #2129 (working on that now).

[carolynvs]

Oh nevermind, it's just the main branch that is affected by that issue.