feat: allow for spack-external (system) python

Change-Id: I605c9d202d89b845d216eac7bcaaef5227d3da75

bin/yashchiki

@@ -172,7 +172,8 @@ env.update({
     # (2.7.18) will pollute the spec and lead to a conflict
     # can be removed as soon as the explicit preferred version
     # is dropped
-    "DEPENDENCY_PYTHON": "python@" + config["dependency_python"],
+    "DEPENDENCY_BUILD_PYTHON": str(int(config["dependency_python"]["build"])),
+    "DEPENDENCY_PYTHON": "python@" + config["dependency_python"]["version"],
     "YASHCHIKI_BUILD_SPACK_GCC": str(int(config["spack_gcc"]["build"])),
     "YASHCHIKI_SPACK_GCC_VERSION": config["spack_gcc"]["version"],
     "YASHCHIKI_SPACK_GCC": "gcc@" + config["spack_gcc"]["version"],

share/yashchiki/styles/asic/config.yaml

 docker_base_image: "rockylinux:8"
 # ECM: it's 3.9.18 really, but that's not yet in the current spack; fix when ready
-dependency_python: "3.9.16"
+dependency_python:
+  build: false
+  version: "3.9.16"
 spack_gcc:
   build: false
   version: "8.5.0"

share/yashchiki/styles/f27/config.yaml

 docker_base_image: "debian:bullseye"
-dependency_python: "3.8.2"
+dependency_python:
+  build: true
+  version: "3.8.2"
 spack_gcc:
   # Whether to build the specified gcc via spack or assume existance.
   build: true

share/yashchiki/styles/visionary/config.yaml

 docker_base_image: "debian:bullseye"
-dependency_python: "3.8.2"
+dependency_python:
+  build: true
+  version: "3.8.2"
 spack_gcc:
   # Whether to build the specified gcc via spack or assume existance.
   build: true