fix(docker): remove custom user creation from the Dockerfile (#109)

Dockerfile

@@ -26,17 +26,8 @@ RUN cargo build --release --locked --no-default-features
 RUN rm -f target/release/deps/git_cliff*
 
 FROM debian:buster-slim as runner
-RUN apt-get update && \
-    apt-get install -y --no-install-recommends \
-    --allow-unauthenticated git \
-    && apt-get clean && rm -rf /var/lib/apt/lists/*
 COPY --from=builder /app/target/release/git-cliff /usr/local/bin
-RUN groupadd -r git && \
-    useradd -r -g git -d /git-home -s /sbin/nologin git-user
 WORKDIR git-home
-RUN chown -R git-user:git /git-home
-USER git-user
-RUN git config --global --add safe.directory '/git-home/app'
 RUN cat <<'EOF' > entrypoint.sh
 #!/bin/sh
 cp -r /app /git-home/app