build(deps): update num requirement from 0.3.0 to 0.4.0

Updates the requirements on [num](https://github.com/rust-num/num) to permit the latest version.
- [Release notes](https://github.com/rust-num/num/releases)
- [Changelog](https://github.com/rust-num/num/blob/master/RELEASES.md)
- [Commits](https://github.com/rust-num/num/compare/num-0.3.0...num-0.4.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Cargo.toml

@@ -22,7 +22,7 @@ datasets = []
 ndarray = { version = "0.15", optional = true }
 nalgebra = { version = "0.23.0", optional = true }
 num-traits = "0.2.12"
-num = "0.3.0"
+num = "0.4.0"
 rand = "0.8.3"
 rand_distr = "0.4.0"
 serde = { version = "1.0.115", features = ["derive"], optional = true }