Declare compatibility with ^10.3 for 2.1.0 release

Looks like this is technically available in Drupal 10.2.x (https://github.com/drupal/drupal/blob/10.2.x/core/core.services.yml), which is what I'd used to test 🐛 RuntimeException: media_library.opener.form_element must be an instance of Drupal\media_library\MediaLibraryOpenerInterface Fixed .

But it is not present in the `core.services.yml` file for 10.1.x.

I guess it would still be better to set the compatibility to ^10.3, since it (a) we don't want people using earlier versions of Drupal 10.2 to use this version of Media Library Form Element and (b) it is only in 10.3 that the autoconfigure key *must* be present to avoid 🐛 RuntimeException: media_library.opener.form_element must be an instance of Drupal\media_library\MediaLibraryOpenerInterface Fixed

Thanks Mark. I'll ping you in edudu on next steps for release.

Automatically closed - issue fixed for 2 weeks with no activity.