feat: add MiniMax-M3 model support (#10837)

Adds inference parameter defaults for the minimax-m3 model family and
includes a vendored patch of upstream llama.cpp PR #24523 to recognize
the minimax-m3 architecture. Once the upstream PR merges, the patch can
be removed and LLAMA_VERSION bumped normally.

Changes:
- backend/cpp/llama-cpp/patches/0001-add-minimax-m3-support.patch:
  vendored patch from ggml-org/llama.cpp#24523 (Preliminary MiniMax-M3
  support). Applied by prepare.sh during the build; keeps the pinned
  LLAMA_VERSION pointing at the latest upstream tag.
- core/config/inference_defaults.json: add minimax-m3 family entry
  (temperature=1.0, top_p=0.95, top_k=40, min_p=0.01,
  repeat_penalty=1.0, matching the existing minimax defaults) and
  register it in the patterns list before the shorter minimax-m2.7
  entry for correct longest-match-first ordering.

Upstream: depends on ggml-org/llama.cpp#24523
Closes: #10820

Signed-off-by: Nandana Dileep <110280757+nandanadileep@users.noreply.github.com>

Author: nandanadileep