Local tasks should honor selected admin interface language (if set)

Hiding files to avoid confusion

Skimmed the code, tested manually and included the manual steps to reproduce the issue.

Concept makes sense, I think the patch still needs work, however.

This comment is clearly outdated:
+ @trigger_error('The string_translation service must be passed to ' . __NAMESPACE__ . '\LocalTaskManager::__construct. It was added in Drupal 9.3.0 and will be required before Drupal 10.0.0.', E_USER_DEPRECATED);

Also, code style is a little weird - camel case local variables are being added next to snake case existing ones.

This change looks like it's makes calls to \Drupal methods instead of using DI:

+++ b/core/lib/Drupal/Core/Menu/Plugin/Block/LocalTasksBlock.php
@@ -86,6 +86,18 @@ public function build() {
     $config = $this->configuration;
     $cacheability = new CacheableMetadata();
     $cacheability->addCacheableDependency($this->localTaskManager);
+
+    $userAdminLangcode = \Drupal::currentUser()->getPreferredAdminLangcode(FALSE);
+    $negotiation_method_enabled = \Drupal::moduleHandler()->moduleExists('language') && \Drupal::service('language_negotiator')->isNegotiationMethodEnabled('language-user-admin');
+

Since you could pass the langcode as an option into the t() call, this seems like a bad idea to change the default langcode:

$this->stringTranslation->setDefaultLangcode($originalLangcode);

Also, I question the approach of setting the langcode when calling getTitle() versus informing the local task plugins about the language they should be using? e.g. set the langcode as part of: LocalTaskManager::createInstance()

I'm also noticing a bug(?) in this local task which is not returning a string:

\Drupal\comment\Plugin\Menu\LocalTask\UnapprovedComments::getTitle()

Or... we should fix the interface/docs

Just a reroll from #68 to 9.5.9 in case some other need if for their projects. #72 and #73 needs to be addressed.

This doesn't seem to work for local tasks added by Views, I guess that's because those translations are stored in config instead of interface translation.

Reroll for 10.1

created a new issue branch "3054641-11.x" for 11.x with patch #77 and claro templates updated. Let's use this for development and then only post static patches based on the MR 4757

Attached is a static patch of MR. 4757 at commit fdb7bfb8.

Not sure if it could be 1 change record but think we will need change records for

new template_process hook + secondary_attributes (not sure if these should be separate)
for new parameter needed for LocalTaskManager

Also may need manual visual testing for the css changes.

Also #76 should that be addressed here?

Reroll for 10.3. No other changes.