🔨: Make Dockerfile compatible with older Docker versions

Dockerfile

@@ -1,7 +1,8 @@
 FROM node:erbium-alpine
 RUN apk add python2
-USER node
 WORKDIR /home/node
-COPY --chown=node:node package.json yarn.lock ./
+COPY package.json yarn.lock ./
+RUN chown node:node -R .
+USER node
 RUN yarn
 ENTRYPOINT node build/dev-server.js