Bump tokio from 1.20.1 to 1.21.2

Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.20.1 to 1.21.2.
- [Release notes](https://github.com/tokio-rs/tokio/releases)
- [Commits](https://github.com/tokio-rs/tokio/compare/tokio-1.20.1...tokio-1.21.2)

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

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

Cargo.lock

@@ -1734,9 +1734,9 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
 [[package]]
 name = "tokio"
-version = "1.20.1"
+version = "1.21.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a8325f63a7d4774dd041e363b2409ed1c5cbbd0f867795e661df066b2b0a581"
+checksum = "a9e03c497dc955702ba729190dc4aac6f2a0ce97f913e5b1b5912fc5039d9099"
 dependencies = [
  "autocfg",
  "bytes",
@@ -1744,7 +1744,6 @@ dependencies = [
  "memchr",
  "mio",
  "num_cpus",
- "once_cell",
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",

Cargo.toml

@@ -23,7 +23,7 @@ clap = { version = "3.2", features = [
   "unicode",
   "wrap_help",
 ] }
-tokio = { version = "1.20", features = ["full"] }
+tokio = { version = "1.21", features = ["full"] }
 futures = "0.3"
 anyhow = "1.0"
 governor = "0.4"