Include python and py-numpy as roots of CI environment

ci/Dockerfile

@@ -249,21 +249,14 @@ ARG parallelism
 ENV SPACK_GROUP=spack
 
 ########################################################################
-# Install developer tooling (py-cmake-format, ruff)
+# Install developer tooling (gersemi, ruff)
 
 RUN <<'INSTALL_DEV_TOOLING'
 set -euo pipefail
 
 # Install developer tooling not needed for CI
 . /entrypoint.sh
 
-# Install py-cmake-format via Spack
-spack --timestamp install --fail-fast -j $parallelism -p 1 \
-  --no-add --only-concrete --no-check-signature \
-  py-cmake-format
-
-spack clean -dfs
-
 # Install ruff and gersemi via pip
 PYTHONDONTWRITEBYTECODE=1 \
   pip --isolated --no-input --disable-pip-version-check --no-cache-dir install \

ci/spack.yaml

@@ -5,8 +5,9 @@ spack:
   - cmake
   - lcov
   - ninja
-  - py-cmake-format
+  - python
   - py-gcovr
+  - py-numpy
   - py-pip # Needed temporarily for ruff installation
   - |
       llvm@21.1.4: +zstd +llvm_dylib +link_llvm_dylib targets=x86