Bump oqs-sys/liboqs from 6e1f49a to 6c20a7d

Bumps [oqs-sys/liboqs](https://github.com/Open-Quantum-Safe/liboqs) from `6e1f49a` to `6c20a7d`.
- [Release notes](https://github.com/Open-Quantum-Safe/liboqs/releases)
- [Commits](open-quantum-safe/liboqs@6e1f49a...6c20a7d)

---
updated-dependencies:
- dependency-name: oqs-sys/liboqs
  dependency-type: direct:production
...

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