Bump tokio-util from 0.6.5 to 0.6.6

Bumps [tokio-util](https://github.com/tokio-rs/tokio) from 0.6.5 to 0.6.6.
- [Release notes](https://github.com/tokio-rs/tokio/releases)
- [Commits](https://github.com/tokio-rs/tokio/compare/tokio-util-0.6.5...tokio-util-0.6.6)

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

Cargo.lock

@@ -3931,9 +3931,9 @@ dependencies = [
 
 [[package]]
 name = "tokio-util"
-version = "0.6.5"
+version = "0.6.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5143d049e85af7fbc36f5454d990e62c2df705b3589f123b71f441b6b59f443f"
+checksum = "940a12c99365c31ea8dd9ba04ec1be183ffe4920102bb7122c2f515437601e8e"
 dependencies = [
  "bytes 1.0.1",
  "futures-core",