Bump tokio from 1.19.2 to 1.20.3

Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.19.2 to 1.20.3.
- [Release notes](https://github.com/tokio-rs/tokio/releases)
- [Commits](https://github.com/tokio-rs/tokio/compare/tokio-1.19.2...tokio-1.20.3)

---
updated-dependencies:
- dependency-name: tokio
  dependency-type: indirect
...

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

Cargo.lock

@@ -2234,16 +2234,16 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
 [[package]]
 name = "tokio"
-version = "1.19.2"
+version = "1.20.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c51a52ed6686dd62c320f9b89299e9dfb46f730c7a48e635c19f21d116cb1439"
+checksum = "664cf6576f16c0ad68184998f3c2d4be9903ede6b291a5b5cfc97d29e0057283"
 dependencies = [
+ "autocfg 1.1.0",
  "bytes",
  "libc",
  "memchr",
  "mio",
  "num_cpus",
- "once_cell",
  "pin-project-lite",
  "socket2",
  "winapi",