refactor: finalize pip-tools Docker wrapper (#260)

Author: Djaytan

docs/user-guide/requirements/pip-compile/Dockerfile

@@ -1,18 +1,19 @@
 # syntax=docker/dockerfile:1.16.0@sha256:e2dd261f92e4b763d789984f6eab84be66ab4f5f08052316d8eb8f173593acf7
 # check=error=true
 
+# BusyBox command help: https://www.busybox.net/downloads/BusyBox.html
 # Note: impossible to rely on v3.13.14 (missing 'cache_clear' function error)
 FROM docker.io/python:3.12.11-alpine@sha256:c610e4a94a0e8b888b4b225bfc0e6b59dee607b1e61fb63ff3926083ff617216
 
-# BusyBox command help: https://www.busybox.net/downloads/BusyBox.html
-RUN addgroup -S pip && \
-    adduser -S -G pip pip
+# New user and group for pip
+RUN addgroup -S -g 1000 pip && \
+    adduser -S -u 1000 -G pip pip
 
-USER pip
+USER 1000:1000
 
-WORKDIR /home/pip/
+ENV HOME=/home/pip
+ENV PATH="${PATH}:${HOME}/.local/bin"
 
-ENV PATH="${PATH}:/home/pip/.local/bin"
+WORKDIR ${HOME}
 
-# Long story short: install pip-tools in the user directory to avoid permission issues.
 RUN pip install --user pip-tools