On case-sensitive systems, the country code needs to be capitalized for
the language to be correctly identified between two dialects. Since
`br` was not capitalized, we fell back on european portuguese for Linux
and MacOS
Fixes https://gitlab.com/kicad/code/kicad/-/issues/15592
This is a test split per requests. While "Latin American Spanish" is
not really homogeneous, there are distinct differences to European
spanish, so we are splitting in an effort to allow both translations.
If one is less viable, this may re-merge in the future.
Updates the Serbian language code from sr_RS to sr. This appears to
work as intended under Debian whereas the full code, despite existing in
the i18n directory was not recognized by wxWidgets or Weblate.