Bump num-bigint from 0.2.6 to 0.4.3

Bumps [num-bigint](https://github.com/rust-num/num-bigint) from 0.2.6 to 0.4.3.
- [Release notes](https://github.com/rust-num/num-bigint/releases)
- [Changelog](https://github.com/rust-num/num-bigint/blob/master/RELEASES.md)
- [Commits](rust-num/num-bigint@num-bigint-0.2.6...num-bigint-0.4.3)

---
updated-dependencies:
- dependency-name: num-bigint
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Cargo.lock

@@ -21,7 +21,7 @@ codec = { package = "parity-scale-codec", version = "3.0.0", features = [
 futures = "0.3.21"
 log = "0.4.17"
 merlin = "2.0"
-num-bigint = "0.2.3"
+num-bigint = "0.4.3"
 num-rational = "0.2.2"
 num-traits = "0.2.8"
 parking_lot = "0.12.0"

client/consensus/babe/Cargo.toml

@@ -15,7 +15,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 
 [dependencies]
 honggfuzz = "0.5.49"
-num-bigint = "0.2"
+num-bigint = "0.4"
 primitive-types = "0.11.1"
 sp-arithmetic = { version = "5.0.0", path = ".." }