Bump futures from 0.3.30 to 0.3.31

Bumps [futures](https://github.com/rust-lang/futures-rs) from 0.3.30 to 0.3.31.
- [Release notes](https://github.com/rust-lang/futures-rs/releases)
- [Changelog](https://github.com/rust-lang/futures-rs/blob/master/CHANGELOG.md)
- [Commits](rust-lang/futures-rs@0.3.30...0.3.31)

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

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

Cargo.toml

@@ -12,7 +12,7 @@ serde_derive = "1.0.152"
 # Wait for wither to relase a new version.
 # https://github.com/thedodd/wither/pull/89#issuecomment-1023644443
 wither = { git = "https://github.com/thedodd/wither" }
-futures = "0.3.30"
+futures = "0.3.31"
 thiserror = "1.0.63"
 axum = { version = "0.6.20", features = ["headers"] }
 tokio = { version = "1.39.3", features = ["full"] }