Sync dockerfile with official

Dockerfile

@@ -20,19 +20,19 @@ RUN git clone -b ${FOCALBOARD_TAG} --depth 1 https://github.com/mattermost/focal
 FROM mattermost/focalboard:${FOCALBOARD_DOCKER_TAG} AS frontend_official
 
 # build the backend
-FROM golang:1.17.2 AS backend
+FROM golang:1.18.3 AS backend
 ARG TARGETARCH=arm
 WORKDIR /focalboard
 COPY --from=repo /focalboard .
 RUN sed -i "s/GOARCH=amd64/GOARCH=${TARGETARCH}/g" Makefile
-RUN make server-linux
+RUN EXCLUDE_PLUGIN=true EXCLUDE_SERVER=true EXCLUDE_ENTERPRISE=true make server-linux
 
 # final image
 FROM debian:buster-slim
 WORKDIR /opt/focalboard
-COPY --from=backend /focalboard/bin/linux/focalboard-server ./bin/
-COPY --from=backend /focalboard/LICENSE.txt ./LICENSE.txt
+COPY --from=backend --chown=nobody:nobody /focalboard/bin/linux/focalboard-server ./bin/
+COPY --from=backend --chown=nobody:nobody /focalboard/LICENSE.txt ./LICENSE.txt
 # COPY --from=frontend /webapp/pack ./pack
-COPY --from=frontend_official /opt/focalboard/pack ./pack
+COPY --from=frontend_official --chown=nobody:nobody /opt/focalboard/pack ./pack
 
 CMD ["/opt/focalboard/bin/focalboard-server"]