docker: Fix permission issues in Dockerfile

Closes #12971
Closes #12970

Dockerfile

@@ -76,14 +76,14 @@ RUN mkdir -p /var/hugo/bin /cache && \
     # See https://github.com/gohugoio/hugo/issues/9810
     runuser -u hugo -- git config --global core.quotepath false
 
+USER hugo:hugo
 VOLUME /project
 WORKDIR /project
-USER hugo:hugo
 ENV HUGO_CACHEDIR=/cache
 ENV PATH="/var/hugo/bin:$PATH"
 
 COPY scripts/docker/entrypoint.sh /entrypoint.sh
-COPY --link --from=dart-sass /out/dart-sass /var/hugo/bin/dart-sass
+COPY --from=dart-sass /out/dart-sass /var/hugo/bin/dart-sass
 
 # Update PATH to reflect the new dependencies.
 # For more complex setups, we should probably find a way to