Remove macOS tch CI test

The macOS tch build is not needed — macOS uses the MLX backend.
Remove the matrix entry and associated macOS-specific steps
(DYLD_LIBRARY_PATH, zip extraction).

Signed-off-by: Michael Yuan <michael@secondstate.io>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: juntao

.github/workflows/ci.yml

@@ -20,11 +20,6 @@ jobs:
             backend: tch
             libtorch-url: https://github.com/second-state/libtorch-releases/releases/download/v2.7.1/libtorch-cxx11-abi-aarch64-2.7.1.tar.gz
             libtorch-archive: libtorch.tar.gz
-          - os: macos-latest
-            name: macOS ARM64 (tch)
-            backend: tch
-            libtorch-url: https://download.pytorch.org/libtorch/cpu/libtorch-macos-arm64-2.7.1.zip
-            libtorch-archive: libtorch.zip
           - os: macos-latest
             name: macOS ARM64 (mlx)
             backend: mlx
@@ -57,12 +52,7 @@ jobs:
 
       - name: Extract libtorch
         if: matrix.backend == 'tch'
-        run: |
-          if [[ "${{ matrix.libtorch-archive }}" == *.zip ]]; then
-            unzip -q ${{ matrix.libtorch-archive }}
-          else
-            tar xzf ${{ matrix.libtorch-archive }}
-          fi
+        run: tar xzf ${{ matrix.libtorch-archive }}
 
       - name: Set linker flags (Linux only)
         if: matrix.backend == 'tch' && runner.os == 'Linux'
@@ -97,10 +87,6 @@ jobs:
         if: matrix.backend == 'tch' && runner.os == 'Linux'
         run: echo "LD_LIBRARY_PATH=${{ github.workspace }}/libtorch/lib:$LD_LIBRARY_PATH" >> "$GITHUB_ENV"
 
-      - name: Set library path (macOS)
-        if: matrix.backend == 'tch' && runner.os == 'macOS'
-        run: echo "DYLD_LIBRARY_PATH=${{ github.workspace }}/libtorch/lib:$DYLD_LIBRARY_PATH" >> "$GITHUB_ENV"
-
       - name: Download 0.6B model
         run: python3 -c "from huggingface_hub import snapshot_download; snapshot_download('Qwen/Qwen3-ASR-0.6B', local_dir='Qwen3-ASR-0.6B')"