Use buildx to build syncer images (#3390)

Signed-off-by: Deepak Kinni <[email protected]>

Author: deepakkinni

hack/release.sh

@@ -147,7 +147,7 @@ function build_driver_images_linux() {
 
 function build_syncer_image_linux() {
   echo "building ${SYNCER_IMAGE_NAME}:${VERSION} for linux"
-  docker build \
+  docker buildx build --platform "linux/$ARCH"\
       -f images/syncer/Dockerfile \
       -t "${SYNCER_IMAGE_NAME}":"${VERSION}" \
       --build-arg "VERSION=${VERSION}" \