Update arm64_graviton.yml

.github/workflows/arm64_graviton.yml

@@ -88,7 +88,6 @@ jobs:
         run: |
           case "${{ matrix.build }}" in
             "make")
-              sed -i -e "s/SMALL_MATRIX_OPT = 1/SMALL_MATRIX_OPT = 0/g" Makefile.system
               make -j$(nproc) DYNAMIC_ARCH=1 USE_OPENMP=0 FC="ccache ${{ matrix.fortran }}"
               ;;
             "cmake")