GHSA-978j-88f3-p5j3 Threshold value is ignored (all shares are n=3)

• crates.io shamir: < 2.0.0 → fixed in 2.0.0

Affected versions of this crate did not properly calculate secret shares requirements. This reduces the security of the algorithm by restricting the crate to always using a threshold value of three, rather than a configurable limit. The flaw was corrected by correctly configuring the threshold.