distutils-r1.eclass: Move setup from src_configure to prepare_all

Move a few minor setup calls from distutils-r1_src_configure()
to distutils-r1_python_prepare_all().  Since we do not declare default
configure sub-phases, it is easy to override src_configure() entirely
and accidentally skip these steps.  We already warn for missing
distutils-r1_python_prepare_all() call, so let's move them there.

Signed-off-by: Michał Górny <mgorny@gentoo.org>

eclass/distutils-r1.eclass

@@ -985,7 +985,10 @@ distutils-r1_python_prepare_all() {
 		python_copy_sources
 	fi
 
+	python_export_utf8_locale
+	[[ ${EAPI} == 6 ]] && xdg_environment_reset # Bug 577704
 	_distutils-r1_print_package_versions
+
 	_DISTUTILS_DEFAULT_CALLED=1
 }
 
@@ -1715,9 +1718,6 @@ distutils-r1_src_configure() {
 	debug-print-function ${FUNCNAME} "${@}"
 	local ret=0
 
-	python_export_utf8_locale
-	[[ ${EAPI} == 6 ]] && xdg_environment_reset # Bug 577704
-
 	if declare -f python_configure >/dev/null; then
 		_distutils-r1_run_foreach_impl python_configure || ret=${?}
 	fi