feat(manager/cargo): support reading package version from workspace (local only)

[viceice]

Changes

Support reading package version from workspace in same manifest.

Context

• https://doc.rust-lang.org/cargo/reference/workspaces.html#the-package-table
• Closes Error parsing Cargo.toml file due to ZoD schema validation error #32528
• Closes fix(manager/cargo): skip non-string package.version #32530

Documentation (please check one with an [x])

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• No documentation update is required

How I've tested my work (please select one)

I have verified these changes via:

• Code inspection only, or
• Newly added/modified unit tests, or
• No unit tests but ran on a real repository, or
• Both unit tests + ran on a real repository