improve user creation and fix rust version

.devcontainer/Dockerfile

@@ -1,4 +1,5 @@
-FROM docker.io/library/rust:1.84.0-bullseye
+# TODO: adopt global version control for rust version
+FROM docker.io/library/rust:1.81.0-bullseye
 ENV SHELL="/bin/bash"
 ENV BASH_FLAGS="-e"
 ENV BIN=/usr/local/bin
@@ -9,7 +10,6 @@ ARG USER_UID=1000
 ARG USER_GID=$USER_UID
 
 # Install basic tools
-#gitlab-cli \
 ARG APT_LIST="\
 jq \
 git \
@@ -18,16 +18,28 @@ curl \
 cmake \
 build-essential \
 "
-RUN set -ex \
+RUN set ${BASH_FLAGS} \
     && apt-get update \
     && apt-get install -y ${APT_LIST} \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/* \
     && echo
 
-# Create the user
-RUN groupadd --gid $USER_GID $USERNAME \
-    && useradd --uid $USER_UID --gid $USER_GID -m $USERNAME \
-    && echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME \
-    && chmod 0440 /etc/sudoers.d/$USERNAME
+# Create dev user `vscode`
+RUN set ${BASH_FLAGS} \
+  && mkdir -p /etc/sudoers.d \
+  && groupadd --force --system sudo \
+  && groupadd --force --gid 127 --system docker \
+  && echo "%sudo ALL=(ALL:ALL) NOPASSWD: ALL" > /etc/sudoers.d/sudo \
+  && groupadd --force --gid ${USER_GID} ${USERNAME} \
+  && useradd \
+    --create-home \
+    --uid ${USER_UID} \
+    --gid ${USER_GID} \
+    --shell $(which bash) \
+    --groups sudo,docker \
+    ${USERNAME} \
+  && echo
 
 # Install GitHub `gh` cli from github.com/cli/cli
 RUN set ${BASH_FLAGS} \