fix: resolve macOS CI cmake installation conflict

- Add brew uninstall cmake before installing to avoid tap conflicts
- Resolves CI failure where cmake from local/pinned tap conflicts with homebrew/core
- Uses --ignore-dependencies and || true for safe uninstall

Author: TrustMeItsCugel

.github/workflows/cross-platform-ffi.yml

@@ -39,6 +39,7 @@ jobs:
     - name: Install system dependencies (macOS)
       if: matrix.os == 'macos-latest'
       run: |
+        brew uninstall --ignore-dependencies cmake || true
         brew install cmake pkg-config
     
     - name: Install system dependencies (Windows)