Bump futures from 0.3.16 to 0.3.19 (#10930)

Bumps [futures](https://github.com/rust-lang/futures-rs) from 0.3.16 to 0.3.19.
- [Release notes](https://github.com/rust-lang/futures-rs/releases)
- [Changelog](https://github.com/rust-lang/futures-rs/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-lang/futures-rs/compare/0.3.16...0.3.19)

---
updated-dependencies:
- dependency-name: futures
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

substrate/client/network/Cargo.toml

@@ -27,7 +27,7 @@ codec = { package = "parity-scale-codec", version = "3.0.0", features = [
 either = "1.5.3"
 fnv = "1.0.6"
 fork-tree = { version = "3.0.0", path = "../../utils/fork-tree" }
-futures = "0.3.9"
+futures = "0.3.19"
 futures-timer = "3.0.2"
 asynchronous-codec = "0.5"
 hex = "0.4.0"

substrate/client/network/test/Cargo.toml

@@ -17,7 +17,7 @@ async-std = "1.10.0"
 sc-network = { version = "0.10.0-dev", path = "../" }
 log = "0.4.8"
 parking_lot = "0.12.0"
-futures = "0.3.9"
+futures = "0.3.19"
 futures-timer = "3.0.1"
 rand = "0.7.2"
 libp2p = { version = "0.40.0", default-features = false }