Use pip constraints file in ngen Dockerfile.

Adding constraints file to ngen (and related) image build to control
numpy and pip versions as needed for compatibility, using this instead
of doing directly within the Dockerfile itself in pip commands.

docker/main/ngen/Dockerfile

@@ -290,12 +290,16 @@ FROM rocky-base as rocky-ngen-packaged-deps
 
 ARG ROCKY_NGEN_DEPS_REQUIRED
 
+# Set up pip constraints file for this and descendent stages
+COPY constraints.txt ${WORKDIR}/constraints.txt
+ENV PIP_CONSTRAINT=${WORKDIR}/constraints.txt
+
 # TODO: later, go back and change all pip3/python3 to just pip/python (but leave for now to limit scope)
 # Note that this includes numpy, which is needed for Python BMI support, regardless of BMI module
 USER root
 RUN dnf update -y && dnf install -y ${ROCKY_NGEN_DEPS_REQUIRED} && dnf clean -y all \
     && ln -s $(which python3) $(which python3 | sed 's/python3/python/') \
-    && pip install --no-cache-dir "pip>=23.0,<23.1" wheel packaging \
+    && pip install --no-cache-dir pip wheel packaging \
     && if [ "${NGEN_WITH_PYTHON}" == "ON" ]; then pip install --no-cache-dir numpy; fi
 USER ${USER}
 

docker/main/ngen/constraints.txt

@@ -0,0 +1,5 @@
+### Constrain pip
+pip>=23.0,<23.1
+
+### Constrain numpy to < 2.0.0 due to current ngen compatibility issue
+numpy~=1.0