Fix issue with python executable

The set(Python_ADDITIONAL_VERSIONS 3 2) line was accidentaly moved after
find_package(PythonInterp REQUIRED), impacting in the value of
PYTHON_EXECUTABLE variable. It was noticed in a CI test for CentOS
Stream8 where the "/usr/bin/python3" was still poiting to "/usr/bin/python3.6"
while "/usr/bin/python3.11" was already present and this impacted the
detection of installed Python modules.
Few other improvements in readability were made in this commit.

CMakeLists.txt

@@ -58,20 +58,6 @@ set(SSG_SHARED_REFS "${SSG_SHARED}/references")
 set(SSG_SHARED_TRANSFORMS "${SSG_SHARED}/transforms")
 set(SSG_UTILS_SCRIPTS "${CMAKE_SOURCE_DIR}/utils")
 
-if(SSG_JINJA2_CACHE_ENABLED)
-    file(MAKE_DIRECTORY "${SSG_JINJA2_CACHE_DIR}")
-    if(NOT EXISTS "${SSG_JINJA2_CACHE_DIR}")
-        message(FATAL_ERROR "jinja2 cache dir was set to '${SSG_JINJA2_CACHE_DIR}'. This directory doesn't seem to exist and attempt to create it has failed.")
-    endif()
-    set(SSG_JINJA2_CACHE_ENABLED_BOOL "true")
-else()
-    set(SSG_JINJA2_CACHE_ENABLED_BOOL "false")
-endif()
-
-message(STATUS "SCAP Security Guide ${SSG_VERSION}")
-message(STATUS "(see ${CMAKE_SOURCE_DIR}/docs/manual/developer_guide.adoc for build instructions)")
-message(STATUS "")
-
 # Content Generation Opetions
 option(SSG_ANSIBLE_PLAYBOOKS_ENABLED "If enabled, Ansible Playbooks for each profile will be built and installed." TRUE)
 option(SSG_ANSIBLE_PLAYBOOKS_PER_RULE_ENABLED "If enabled, Ansible Playbooks for each rule will be built and installed." FALSE)
@@ -139,7 +125,11 @@ if("$ENV{PYTHONPATH}" STREQUAL "")
 else()
     set(ENV{PYTHONPATH} "${PROJECT_SOURCE_DIR}:$ENV{PYTHONPATH}")
 endif()
+message(STATUS "PYTHONPATH: $ENV{PYTHONPATH}")
 
+# Setting Python_ADDITIONAL_VERSIONS before calling PythonInterp can influence the priority of
+# python executables in a scenario where multiple versions are present.
+set(Python_ADDITIONAL_VERSIONS 3 2)
 # Required Packages
 find_package(PythonInterp REQUIRED)
 find_package(OpenSCAP REQUIRED)
@@ -150,16 +140,18 @@ find_program(BATS_EXECUTABLE NAMES bats)
 find_program(GIT_EXECUTABLE NAMES git)
 find_program(GREP_EXECUTABLE NAMES grep)
 find_program(LINKCHECKER_EXECUTABLE NAMES linkchecker)
-find_program(PYTHON3_EXECUTABLE NAMES python3)
 find_program(SED_EXECUTABLE NAMES sed REQUIRED)
 find_program(SHELLCHECK_EXECUTABLE NAMES shellcheck)
 find_program(XMLLINT_EXECUTABLE NAMES xmllint REQUIRED)
 find_program(XSLTPROC_EXECUTABLE NAMES xsltproc REQUIRED)
 find_program(YAMLLINT_EXECUTABLE NAMES yamllint)
 
 message(STATUS "")
-message(STATUS "Find Python Modules:")
-set(Python_ADDITIONAL_VERSIONS 3 2)
+message(STATUS "SCAP Security Guide ${SSG_VERSION}")
+message(STATUS "(see ${CMAKE_SOURCE_DIR}/docs/manual/developer_guide.adoc for build instructions)")
+
+message(STATUS "")
+message(STATUS "Finding Python Modules:")
 find_python_module(jinja2 REQUIRED)
 find_python_module(yaml REQUIRED)
 find_python_module(cmakelint)
@@ -219,10 +211,20 @@ if(NOT SSG_THIN_DS)
     set(SSG_THIN_DS_RULE_ID "off")
 endif()
 
+if(SSG_JINJA2_CACHE_ENABLED)
+    file(MAKE_DIRECTORY "${SSG_JINJA2_CACHE_DIR}")
+    if(NOT EXISTS "${SSG_JINJA2_CACHE_DIR}")
+        message(FATAL_ERROR "jinja2 cache dir was set to '${SSG_JINJA2_CACHE_DIR}'. This directory doesn't seem to exist and attempt to create it has failed.")
+    endif()
+    set(SSG_JINJA2_CACHE_ENABLED_BOOL "true")
+else()
+    set(SSG_JINJA2_CACHE_ENABLED_BOOL "false")
+endif()
+
 configure_file("${CMAKE_SOURCE_DIR}/build_config.yml.in" "${CMAKE_BINARY_DIR}/build_config.yml" @ONLY)
 
 message(STATUS " ")
-message(STATUS "Python Tools and Modules:")
+message(STATUS "Summary of Python Tools and Modules:")
 # Required Python Tools
 message(STATUS "python: ${PYTHON_EXECUTABLE} (version: ${PYTHON_VERSION_STRING})")
 message(STATUS "python yaml module: ${PY_YAML}")
@@ -246,7 +248,7 @@ message(STATUS "python sphinx module (optional): ${PY_SPHINX}")
 message(STATUS "python sphinxcontrib.autojinja module (optional): ${PY_SPHINXCONTRIB.AUTOJINJA}")
 message(STATUS "python sphinx_rtd_theme module (optional): ${PY_SPHINX_RTD_THEME}")
 message(STATUS " ")
-message(STATUS "System Tools:")
+message(STATUS "Summary of System Tools:")
 # Required System Tools
 message(STATUS "oscap: ${OPENSCAP_OSCAP_EXECUTABLE} (version: ${OSCAP_VERSION})")
 message(STATUS "sed: ${SED_EXECUTABLE}")
@@ -257,35 +259,35 @@ message(STATUS "ansible-lint module (optional): ${ANSIBLE_LINT_EXECUTABLE}")
 message(STATUS "ansible-playbook module (optional): ${ANSIBLE_PLAYBOOK_EXECUTABLE}")
 message(STATUS "BATS framework (optional): ${BATS_EXECUTABLE}")
 message(STATUS "grep (optional): ${GREP_EXECUTABLE}")
-message(STATUS "shellcheck (optional): ${SHELLCHECK_EXECUTABLE}")
 message(STATUS "linkchecker (optional): ${LINKCHECKER_EXECUTABLE}")
+message(STATUS "shellcheck (optional): ${SHELLCHECK_EXECUTABLE}")
 message(STATUS "yamllint module (optional): ${YAMLLINT_EXECUTABLE}")
 
 message(STATUS " ")
 message(STATUS "CMake Settings:")
 message(STATUS "build type: ${CMAKE_BUILD_TYPE}")
+message(STATUS "build directory: ${CMAKE_BINARY_DIR}")
 message(STATUS "generator: ${CMAKE_GENERATOR}")
 message(STATUS "source directory: ${CMAKE_SOURCE_DIR}")
-message(STATUS "build directory: ${CMAKE_BINARY_DIR}")
-message(STATUS "Logging: ${SSG_LOG}")
 
 message(STATUS " ")
 message(STATUS "Build options:")
 message(STATUS "SSG vendor string: ${SSG_VENDOR}")
 message(STATUS "Target OVAL version: ${SSG_TARGET_OVAL_VERSION}")
+message(STATUS "Logging: ${SSG_LOG}")
 message(STATUS "Ansible Playbooks: ${SSG_ANSIBLE_PLAYBOOKS_ENABLED}")
 message(STATUS "Ansible Playbooks Per Rule: ${SSG_ANSIBLE_PLAYBOOKS_PER_RULE_ENABLED}")
 message(STATUS "Bash scripts: ${SSG_BASH_SCRIPTS_ENABLED}")
-message(STATUS "STIG Delta Taloring files: ${SSG_BUILD_DISA_DELTA_FILES}")
+message(STATUS "Build SCE Content: ${SSG_SCE_ENABLED}")
+message(STATUS "Build SRG XLSX Export: ${SSG_SRG_XLSX_EXPORT}")
 if(SSG_JINJA2_CACHE_ENABLED)
     message(STATUS "jinja2 cache: enabled")
     message(STATUS "jinja2 cache dir: ${SSG_JINJA2_CACHE_DIR}")
 else()
     message(STATUS "jinja2 cache: disabled")
 endif()
-message(STATUS "Build SCE Content: ${SSG_SCE_ENABLED}")
-message(STATUS "Build SRG XLSX Export: ${SSG_SRG_XLSX_EXPORT}")
 message(STATUS "Separate SCAP files: ${SSG_SEPARATE_SCAP_FILES_ENABLED}")
+message(STATUS "STIG Delta Taloring files: ${SSG_BUILD_DISA_DELTA_FILES}")
 message(STATUS "Thin data streams: ${SSG_THIN_DS}")
 
 message(STATUS " ")