Remove unnecessary dependencies.

Found by "cargo udeps"

Cargo.lock

@@ -546,12 +546,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "fs_extra"
-version = "1.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2022715d62ab30faffd124d40b76f4134a550a87792276512b18d63272333394"
-
 [[package]]
 name = "funty"
 version = "1.1.0"
@@ -1185,7 +1179,6 @@ dependencies = [
  "clap",
  "crc32c",
  "daemonize",
- "fs_extra",
  "futures",
  "hex",
  "humantime",
@@ -1199,21 +1192,17 @@ dependencies = [
  "rand",
  "regex",
  "routerify",
- "rust-s3",
  "scopeguard",
  "serde",
  "serde_json",
  "slog",
- "slog-async",
  "slog-scope",
  "slog-stdlog",
  "slog-term",
  "tar",
  "thiserror",
  "tokio",
- "tokio-stream",
  "toml",
- "walkdir",
  "workspace_hack",
  "zenith_metrics",
  "zenith_utils",