Remove changing user

Dockerfile

@@ -21,16 +21,3 @@ RUN flutter config --enable-web
 RUN flutter upgrade
 RUN flutter precache
 RUN flutter --version
-
-# Set user and group
-ARG user=builduser
-ARG group=builduser
-ARG uid=1000
-ARG gid=1000
-RUN groupadd -g ${gid} ${group}
-RUN useradd -u ${uid} -g ${group} -s /bin/sh -m ${user}
-
-RUN chown -R ${uid}:${gid} ${FLUTTER_ROOT}
-
-# Switch to user
-USER ${uid}:${gid}