rust-ansi-term will be removed from Debian soon. Please stop using
rust-ansi-term. Many projects have switched to rust-nu-ansi-term. The
sniffglue packaging has a patch that shows a simple way to switch that
might work for this project.

Please also report this issue upstream. You can mention this:
https://rustsec.org/advisories/RUSTSEC-2021-0139.html

Thank you,
Jeremy Bícha