cargo: bump async-tar from 0.3.0 to 0.4.2

Bumps [async-tar](https://github.com/dignifiedquire/async-tar) from 0.3.0 to 0.4.2.
- [Release notes](https://github.com/dignifiedquire/async-tar/releases)
- [Commits](dignifiedquire/async-tar@v0.3.0...v0.4.2)

---
updated-dependencies:
- dependency-name: async-tar
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Cargo.lock

@@ -22,7 +22,7 @@ async-native-tls = { version = "0.3" }
 async-smtp = { git = "https://github.com/async-email/async-smtp", branch="master", features = ["socks5"] }
 async-std-resolver = "0.20"
 async-std = { version = "1", features = ["unstable"] }
-async-tar = "0.3"
+async-tar = "0.4"
 async-trait = "0.1"
 backtrace = "0.3"
 base64 = "0.13"