Bump futures-sink from 0.3.8 to 0.3.12

Bumps [futures-sink](https://github.com/rust-lang/futures-rs) from 0.3.8 to 0.3.12.
- [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/0.3.8...0.3.12)

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

Cargo.lock

@@ -1848,9 +1848,9 @@ dependencies = [
 
 [[package]]
 name = "futures-sink"
-version = "0.3.8"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f878195a49cee50e006b02b93cf7e0a95a38ac7b776b4c4d9cc1207cd20fcb3d"
+checksum = "caf5c69029bda2e743fddd0582d1083951d65cc9539aebf8812f36c3491342d6"
 
 [[package]]
 name = "futures-task"