armbian-next: Python tooling: use consolidated+hashed+cached pip base/pycache; don't pip during Dockerfile build, nor cli-requirements

- consolidate at `prepare_python_and_pip()`
- sanity check for Python version 3.9+ regardless of HOSTRELEASE
- TODO: pip vs sudo/root: need pip 22.2+ to curb warning, not doing it

lib/functions/cli/cli-requirements.sh

@@ -17,11 +17,11 @@ function cli_requirements_pre_run() {
 function cli_requirements_run() {
 	initialize_extension_manager # initialize the extension manager.
 	declare -a -g host_dependencies=()
-	
+
 	obtain_and_check_host_release_and_arch # Sets HOSTRELEASE & validates it for sanity; also HOSTARCH
 	host_release="${HOSTRELEASE}" host_arch="${HOSTARCH}" early_prepare_host_dependencies
-	
+
 	LOG_SECTION="install_host_dependencies" do_with_logging install_host_dependencies "for requirements command"
-	LOG_SECTION="prepare_pip_packages_for_python_tools" do_with_logging prepare_pip_packages_for_python_tools
+
 	display_alert "Done with" "@host dependencies" "cachehit"
 }