[Pkg-rust-maintainers] Bug#946921: (rust-spin) Project abandoned

[Wolfgang Silbermayr]

It looks like the project returned form the hiatus half a year ago, so this
issue is no longer a problem for crates that use newer versions of `spin` so
it's rather a matter of upgrading those in unstable after bullseye has been
released.

Further information on the RustSec entry:

https://github.com/RustSec/advisory-db/issues/830
https://github.com/RustSec/advisory-db/pull/423