feature: added docker buildx

Dockerfile

@@ -45,3 +45,5 @@ RUN set -o errexit -o nounset && echo "Installing build dependencies" && \
     sed --in-place 's|startGroovy ( ) {|startGroovy ( ) {\n JAVA_OPTS="$JAVA_OPTS --add-modules=ALL-SYSTEM"|' "${GROOVY_HOME}/bin/startGroovy"
 
 RUN apk add --no-cache openssh-client
+
+COPY --from=docker/buildx-bin /buildx /usr/libexec/docker/cli-plugins/docker-buildx