Bump libntech from 3b5afdb to c6015b4

Bumps [libntech](https://github.com/NorthernTechHQ/libntech) from `3b5afdb` to `c6015b4`.
- [Release notes](https://github.com/NorthernTechHQ/libntech/releases)
- [Commits](NorthernTechHQ/libntech@3b5afdb...c6015b4)

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

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Author: dependabot[bot]