Use nproc instead of action step for getting CPU cores

Author: EZForever

.github/workflows/build.yml

@@ -47,10 +47,6 @@ jobs:
           repository: ggml-org/llama.cpp
           path: repo
 
-      - name: Get number of CPU cores
-        uses: SimenB/github-actions-cpu-cores@v2
-        id: cpu-cores
-
       - name: Setup Alpine Linux
         uses: jirutka/setup-alpine@v1
         with:
@@ -59,7 +55,7 @@ jobs:
       - name: CMake
         run: |
           cmake repo -B build -DCMAKE_BUILD_TYPE=Release -DCMAKE_EXE_LINKER_FLAGS="-static" -DGGML_NATIVE=OFF -DGGML_STATIC=ON -DGGML_RPC=ON -DGGML_CCACHE=OFF -DGGML_OPENMP=OFF -DLLAMA_BUILD_SERVER=ON -DLLAMA_CURL=OFF -DBUILD_SHARED_LIBS=OFF ${{ matrix.ssl_defines }} ${{ matrix.avx_defines }}
-          cmake --build build --config Release --target llama-server --target rpc-server -j ${{ steps.cpu-cores.outputs.count }}
+          cmake --build build --config Release --target llama-server --target rpc-server -j $(nproc)
           strip build/bin/*
         shell: alpine.sh {0}