GHSA-xx64-wwv2-hcqq: astral-tokio-tar: `unpack_in` can chmod arbitrary directories by following symlinks

In versions 0.6.0 and earlier of astral-tokio-tar, the unpack_in API could inadvertently modify the permissions of external (i.e. non-archive) directories outside of the archive. An attacker could use this to contrite a tar archive that maliciously changes directory permissions outside of its intended hierarchy. This flaw only affects directories; individual file permissions cannot be modified via it.

See GHSA-j4xf-2g29-59ph for the equivalent flaw in the tar crate.