English is listed as a translation language

Problem/Motivation

Drupal 7's l10n_community_get_languages() leaves English out everywhere: it is the source language, not a translation target. On 3.0.x most listings use the language manager directly, so English shows up on the explore languages page, in the language count of the projects page, in the pick-and-go form, in the language progress block and in the packager's language loop, where it would get its own packaged file per release.

Proposed resolution

Add an l10n_community.languages service with getTranslationLanguages(), the port of the Drupal 7 helper, and use it in every listing: explore languages, projects page count, pick-and-go, language progress block, project overview and status tables, packager and packager settings form.

Tests: the Drupal 7 language listing test asserts English is absent (passes there), and the port L10nLanguagesProjectsTest asserts the same.

LLM disclosure

LLM was used to find, diagnose explain and fix this issue. With human review.