drop ccache and ARCH in xbuild

.github/workflows/dynamic_arch.yml

@@ -306,4 +306,4 @@ jobs:
 
       - name: Build OpenBLAS
         run: |
-          make -j$(nproc) HOSTCC="ccache gcc" CC="ccache ${{ matrix.triple }}-gcc" FC="ccache ${{ matrix.triple }}-gfortran" ARCH=${{ matrix.target }} ${{ matrix.opts }}
+          make -j$(nproc) HOSTCC=gcc CC="ccache ${{ matrix.triple }}-gcc" FC="ccache ${{ matrix.triple }}-gfortran" ${{ matrix.opts }}