No workflow for upgrading recursive dependencies if root dependencies are up-to-date

The current design for `cargo upgrade` is as a replacement for `cargo update` but we only do recursive compatible upgrades if we modified one of the root crates. You can't just run `cargo upgrade` and upgrade the indirect dependencies.

The issue names no files, tests, or entry points. Start by tracing how `cargo upgrade` decides whether to update dependencies and compare that behavior with `cargo update`; done should include a defined workflow that upgrades indirect dependencies when root dependencies are already current.

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