i18n: ensure consistent indent style for next locales (#7205)

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7205
Reviewed-by: floss4good <floss4good@noreply.codeberg.org>
Reviewed-by: Gusted <gusted@noreply.codeberg.org>

.editorconfig

@@ -26,3 +26,8 @@ insert_final_newline = false
 
 [options/locale/locale_*.ini]
 insert_final_newline = false
+
+# Weblate JSON output defaults to four spaces
+[options/locale_next/locale_*.json]
+indent_style = space
+indent_size = 4