Recent changes to `cargo-auditable-cargo-wrapper` and `librsvg`
caused it to ignore the user's decision to opt out of `cargo-audit`
functionality, partially because `librsvg` does not use
`buildRustPackage`.
This commit restores the single-point-of-opt-out from this mis-named
functionality: `cargo-auditable.meta.broken`.
Co-authored-by: figsoda <figsoda@pm.me>