Bump llama.cpp from ac43576 to fe680e3

Bumps [llama.cpp](https://github.com/ggerganov/llama.cpp) from `ac43576` to `fe680e3`.
- [Release notes](https://github.com/ggerganov/llama.cpp/releases)
- [Commits](ggerganov/llama.cpp@ac43576...fe680e3)

---
updated-dependencies:
- dependency-name: llama.cpp
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>