feat: Use correct dockerfile env variables

Author: alex289

Dockerfile

@@ -1,6 +1,6 @@
 FROM node:22-slim
 
-ENV NODE_ENV production
+ENV NODE_ENV=production
 LABEL org.opencontainers.image.authors="Timo Kössler <info@timokoessler.de>"
 LABEL org.opencontainers.image.title="Docker Deploy API"
 LABEL org.opencontainers.image.description="An easy-to-use API for deploying Docker containers"
@@ -10,8 +10,8 @@ RUN echo "#!/bin/sh\nnode cli.js \$@" > /usr/local/bin/cli && \
 
 USER node
 WORKDIR /home/node
-ENV NODE_ENV production
-ENV IS_DOCKER true
+ENV NODE_ENV=production
+ENV IS_DOCKER=true
 
 COPY --chown=node:node ./dist/ ./