chore: bump mlx-swift-lm to pick up the Qwen35 and LFM2VL unit tests (#149)

Points at c09851f, which carries both:

- SharpAI/mlx-swift-lm#51 — the hybrid full-attention/GatedDeltaNet split in
  MLXVLM/Models/Qwen35.swift, gated by a fixed period (full_attention_interval)
- SharpAI/mlx-swift-lm#52 — the hybrid attention/short-conv split in
  MLXVLM/Models/LFM2VL.swift, gated by explicit layer indices (full_attn_idxs)

Both were, alongside Gemma4 (#147) and Qwen3VL (#148), among the largest
zero-coverage files in the model layer. Coverage: Qwen35 0% → 66.4%,
LFM2VL 0% → 34.9%.

No SwiftLM-side code changes; verified the umbrella builds clean against the
bumped pointer.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

Author: solderzzc