build.sh: Pass --without-zstd for binutils (macOS fix)

When building fat binaries for mavOS we got the following error:

  ld: warning: ignoring file /usr/local/Cellar/.../libzstd.dylib,
  building for macOS-arm64 but attempting to link with file built
  for macOS-x86_64

build.sh

@@ -174,6 +174,7 @@ if [ "$BUILD_BINUTILS" == "yes" ] ; then
         --target="$TARGET" \
         --disable-gdb \
         --disable-sim \
+        --without-zstd \
         > "${LATEST_LOG}" 2>&1
 
     echo "  Building..."