Update getrandom requirement from 0.3 to 0.4

Updates the requirements on [getrandom](https://github.com/rust-random/getrandom) to permit the latest version.
- [Changelog](https://github.com/rust-random/getrandom/blob/master/CHANGELOG.md)
- [Commits](rust-random/getrandom@v0.3.0...v0.4.1)

---
updated-dependencies:
- dependency-name: getrandom
  dependency-version: 0.4.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Cargo.toml

@@ -47,7 +47,7 @@ async-channel = "2.0.0"
 async-net = "2.0.0"
 blocking = "1"
 criterion = { version = "0.7", default-features = false, features = ["cargo_bench_support"] }
-getrandom = "0.3"
+getrandom = "0.4"
 signal-hook = "0.3"
 tempfile = "3"