[PR #6774/3fd4cdb1 backport][stable-7] locale_gen: works with C.UTF-8 (#6818)

locale_gen: works with C.UTF-8 (#6774)

* locale_gen: fix

* test working with C.UTF-8

* working with locale eo

* handle C.UTF-8 edge cases

* grammatic pedantism

* add changelog frag

* add doc about specific OS support

* update changelog frag

(cherry picked from commit 3fd4cdb119)

Co-authored-by: Alexei Znamensky <103110+russoz@users.noreply.github.com>

tests/integration/targets/locale_gen/tasks/main.yml

@@ -8,5 +8,11 @@
 # GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-- include_tasks: 'locale_gen.yml'
-  when: ansible_distribution in ('Ubuntu', 'Debian')
+- name: Bail out if not supported
+  ansible.builtin.meta: end_play
+  when: ansible_distribution not in ('Ubuntu', 'Debian')
+
+- include_tasks: basic.yml
+  loop: "{{ locale_list_basic }}"
+  loop_control:
+    loop_var: locale_basic