Revert "Customize container user permissions using PUID and PGID. #9657"

This reverts commit 97c90f1e69.

Dockerfile

@@ -165,8 +165,7 @@ RUN apk update && apk upgrade && \
         tzdata \
         libedit \
         libldap \
-        libcap \
-        su-exec && \
+        libcap && \
     rm -rf /var/cache/apk/*
 
 # Copy in the Python packages
@@ -207,6 +206,8 @@ RUN /venv/bin/python3 -m pip install --no-cache-dir gunicorn==23.0.0 && \
     echo "pgadmin ALL = NOPASSWD: /usr/sbin/postfix start" > /etc/sudoers.d/postfix && \
     echo "pgadminr ALL = NOPASSWD: /usr/sbin/postfix start" >> /etc/sudoers.d/postfix
 
+USER 5050
+
 # Finish up
 VOLUME /var/lib/pgadmin
 EXPOSE 80 443