Bump openssl in /backend-rs in the cargo group across 1 directory (#59)

Bumps the cargo group with 1 update in the /backend-rs directory: [openssl](https://github.com/sfackler/rust-openssl).


Updates `openssl` from 0.10.66 to 0.10.70
- [Release notes](https://github.com/sfackler/rust-openssl/releases)
- [Commits](https://github.com/sfackler/rust-openssl/compare/openssl-v0.10.66...openssl-v0.10.70)

---
updated-dependencies:
- dependency-name: openssl
dependency-type: indirect
dependency-group: cargo
...

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