chore(backport): Use uv during Dockerfile build (#2503)

* Backport:
   - PR #2485
   - PR #2486
   - parts of PR #2461

---------

Co-authored-by: Matthew Feickert <matthew.feickert@cern.ch>

docker/Dockerfile

@@ -1,23 +1,25 @@
-ARG BASE_IMAGE=python:3.11-slim-bullseye
+ARG BASE_IMAGE=python:3.12-slim-bullseye
 # hadolint ignore=DL3006
 FROM ${BASE_IMAGE} as base
 
 FROM base as builder
 # Set PATH to pickup virtual environment by default
 ENV PATH=/usr/local/venv/bin:"${PATH}"
 COPY . /code
-# hadolint ignore=DL3003,SC2102
+# hadolint ignore=DL3003,SC2102,SC1091
 RUN apt-get -qq -y update && \
     apt-get -qq -y install --no-install-recommends \
         git && \
     apt-get -y autoclean && \
     apt-get -y autoremove && \
     rm -rf /var/lib/apt/lists/* && \
     python -m venv /usr/local/venv && \
+    . /usr/local/venv/bin/activate && \
     cd /code && \
-    python -m pip --no-cache-dir install --upgrade pip setuptools wheel && \
-    python -m pip --no-cache-dir install '.[xmlio,contrib]' && \
-    python -m pip list
+    python -m pip --no-cache-dir install --upgrade uv && \
+    uv pip install --no-cache --upgrade pip setuptools wheel && \
+    uv pip install --no-cache '.[xmlio,contrib]' && \
+    uv pip list
 
 FROM base
 
@@ -59,4 +61,8 @@ ENV LANG=C.UTF-8
 
 ENV PATH=${HOME}/.local/bin:${PATH}
 
+# The first ever run of the CLI API incurs some overhead so do that during the
+# build instead of making the user wait
+RUN pyhf --version
+
 ENTRYPOINT ["/usr/local/venv/bin/pyhf"]