This module breaks Bootstrap 3 features (e.g. carousel)

The module has been upgraded to use Bootstrap 5, but the bootstrap-languages project still uses Bootstrap 3, I just forked the project (https://github.com/danrod96/bootstrap-languages) and I am working on upgrading the project to Bootstrap 5.

Is there a way to make this module Bootstrap version independent?
The Drupal Bootstrap 3 is still used by roughly 115.000 pages vs approx. 5.000 with Bootstrap 5.

I would argue, that we do not need to download additional JS and CSS in languages_dropdown.libraries.yml if the underlying theme is Bootstrap. So in essence, we have to remove the last line to avoid any bootstrap version conflicts:

dependency-js:
  remote: https://github.com/FezVrasta/popper.js
  version: VERSION
  license:
    name: MIT
    url: https://github.com/FezVrasta/popper.js/blob/master/LICENSE.md
    gpl-compatible: true
  js:
    https://cdnjs.cloudflare.com/ajax/libs/popper.js/2.9.2/umd/popper.min.js: { type: external, minified: true }
    <strong>https://cdn.jsdelivr.net/npm/bootstrap@5.3.1/dist/js/bootstrap.bundle.min.js: { type: external, minified: true }</strong>

So, here is something that worked for me - removed the bootstrap CSS.
In case the language selector has to work also on non-bootstrap themes, I would suggest to leave the styling to the site builders and also avoid adding the bootstrap CSS, as it currently conflicts with non-bootstrap themes (e.g. Adminimal).

This isn't working for me for non-bootstrap themes at all, I need the BS Js to load.

For a non-bootstrap theme the JS is loaded. I disabled the CSS.

@danrod
we could re-version released to target bootstrap 3,4,5 themes. then we know the theme has the 'right js version'.