build(deps): update openssl requirement in /bindings/rust/extended

Updates the requirements on [openssl](https://github.com/sfackler/rust-openssl) to permit the latest version.
- [Release notes](https://github.com/sfackler/rust-openssl/releases)
- [Commits](sfackler/rust-openssl@openssl-errors-v0.1.0...openssl-v0.10.70)

---
updated-dependencies:
- dependency-name: openssl
  dependency-type: direct:production
...

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

bindings/rust/extended/s2n-tls/Cargo.toml

@@ -30,7 +30,7 @@ hex = "0.4"
 futures-test = "0.3"
 # The openssl crate broke MSRV with 0.10.67
 # TODO unpin this once fixed - https://github.com/sfackler/rust-openssl/issues/2317
-openssl = "<0.10.67"
+openssl = "<0.10.71"
 openssl-sys = "0.9"
 foreign-types = "0.3"
 temp-env = "0.3"