Menu link of default language overwritten by translations if translation not enabled

I opened a merge request that addresses this with a new approach. Simply, if a menu link is not translatable, the code should not be setting a language on the menu link entity.

Here are some test step that fail without the fix applied:
1. drush si
2. drush en -y workspaces content_translation
3. drush uli
4. Go to /admin/config/regional/language and add the Spanish language
5. Go to /admin/config/regional/content-language and enable translation for "Content", ensure to check "Article" under the "Content" fieldset
6. Switch to the Stage workspace
7. Create a new Article, check "Provide a menu link" and save
8. Go to /es/node/{}/translations and add a Spanish translation
9. Note the revision ID: drush sqlq "select MAX(revision_id) from menu_link_content_field_revision"
10. Run drush php:eval 'echo \Drupal::entityTypeManager()->getStorage("menu_link_content")->loadRevision(REVISION_ID)->getMenuName()'

Notice that without the fix, the menu name comes blank, but with the fix, it prints the menu name.

The test fail does not seem related to this:
Drupal\Tests\image\Functional\ImageStylesPathAndUrlTest 0 passes 84s 1 fails

Looks good to me but we need tests: converting #31 would be a good start :)