Drupal install throwing "Translation file not found" notice for "en" langcode when "translate_english" is set to false

Changing $languages = \Drupal::languageManager()->getLanguages(); to $languages = locale_translatable_language_list(); in /core/includes/install.core.inc didn't solve my problem. Still getting errors like "Admin Toolbar (3.3.0). File not found at https://ftp.drupal.org/files/translations/all/admin_toolbar/admin_toolba..." errors for all module translations. I also got a lot of strings in a wrong other language.

I have currently only English as language and "Enable interface translation to English" is true.

I really need a solution for this annoying problem. Running Drupal 9.5.7

Same issue since Drupal 9.x
drush locale:check locale:update show errors 404 aswells as updating from backoffice.
The reason, it's trying to get en.po files which doesn't exists instead of en-GB.po files.

Thanks.... no more log entries with 'tanslation files not found'...

@tobiasb based on your comment #5 I assume you mean that there should be a hard exclusion for "en" in code?

So Drupal skips early for cases like
https://ftp.drupal.org/files/translations/all/simple_sitemap/simple_site....en.po.

right?

@jordan.jamous could you create your patch as MR?

We should also add a test which reproduces the issue (simply checks the log entry for that case) to ensure it's broken without and working with the patch. The steps can be seen above, I think it's jus the case if English is enabled, but not the standard language?

I have this problem in two sites, both have only English and Dutch installed and enabled. Site 1: Dutch as default, site 2: English is default.

I am seeing a lot of English translation file not found errors for all contrib modules (for example https://ftp.drupal.org/files/translations/all/metatag/metatag-2.0.2.en.po.) at every Cron run, in a site where the default language is not English, and it's filling up the database log.

Since this might be affecting all installations using any other language than English (which is a lot) I think that this is not a small issue, so raising Priority.

I have created an MR based on the patch by @jordan.jamous (thanks!) to hopefully get this issue moving. Perhaps someone can create a test?

Totally agree with @ressa and can confirm it does ;)