Skip checking crate for [bans.workspace.duplicates] (interaction with cargo-hakari)

[jalil-salame]

Is your feature request related to a problem? Please describe.
When using [bans.workspace.duplicates] with cargo-hakari, duplicates are reported for the workspace-hack crate. As this crate is auto-generated, this is not an error (but it is everywhere else).

Describe the solution you'd like
Adding a [bans.workspace.skip] field that allows you to opt out of checks in specific workspace crates.

Describe alternatives you've considered

• Adapting cargo-hakari to generate { workspace = true } instead of setting the version, but this seems to not be feasible.
• Replacing the workspace-hack/Cargo.toml with a dummy before running cargo-deny