Bump async-compression from 0.4.20 to 0.4.21

Bumps [async-compression](https://github.com/Nullus157/async-compression) from 0.4.20 to 0.4.21.
- [Release notes](https://github.com/Nullus157/async-compression/releases)
- [Changelog](https://github.com/Nullus157/async-compression/blob/main/CHANGELOG.md)
- [Commits](Nullus157/async-compression@v0.4.20...v0.4.21)

---
updated-dependencies:
- dependency-name: async-compression
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

Cargo.lock

@@ -20,7 +20,7 @@ lading-payload = { version = "0.1", path = "../lading_payload" }
 lading-throttle = { version = "0.1", path = "../lading_throttle" }
 lading-signal = { version = "0.1", path = "../lading_signal" }
 
-async-compression = { version = "0.4.20", features = ["tokio", "zstd"] }
+async-compression = { version = "0.4.21", features = ["tokio", "zstd"] }
 average = { version = "0.15", default-features = false, features = [] }
 bollard = { version = "0.18", default-features = false, features = ["pipe", "http"] }
 byte-unit = { workspace = true }