locale_gen: add testcase for de_CH.utf8 (#9176)

Author: russoz

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

@@ -24,3 +24,6 @@ locale_list_basic:
       - tr_CY.UTF-8
       - tr_CY.utf8
     skip_removal: false
+  - localegen: de_CH.UTF-8
+    locales: [de_CH.utf8]
+    skip_removal: false