`serd` was removed from crates.io for malicious code

This crate was part of a typosquatting malware cluster published by the malicious user `amaperf` and contained a malware payload in build.rs to exfiltrate host information to the attacker.

This advisory is to retrospectively document this attempted attack. The version information and download records of the malicious crate are no longer available. The related malicious crates have been yanked, and the malicious account has been banned.

Thanks to [Veracode](https://www.veracode.com/) (formerly phylum)for
reporting this to the crates.io team!