During a target rollback, the client fails to detect the rollback for delegated targets. This could cause the client to fetch a target from an incorrect source, altering the target contents. Users should upgrade to tough version 0.20.0 or later and ensure any forked or derivative code is patched to incorporate the new fixes.

Affected: crates.io: tough

## Summary

When updating the snapshot role, TUF clients should ensure that any previously encountered targets or delegated targets metadata files continue to be present in new snapshot metadata files. Likewise, the new targets and delegated targets metadata versions must be greater than or equal to the previously encountered versions. While tough will perform this check for targets metadata files, it did not perform this check for dele…