remove more deprecations

src/Commands/IslandoraCommands.php

@@ -122,7 +122,7 @@ class IslandoraCommands extends DrushCommands {
       $account = $this->entityTypeManager->getStorage('user')->load($userid);
       $userSession = new UserSession([
         'uid'   => $account->id(),
-        'name'  => $account->getUsername(),
+        'name'  => $account->getDisplayName(),
         'roles' => $account->getRoles(),
       ]);
       $this->accountSwitcher->switchTo($userSession);

src/Plugin/Condition/MediaSourceHasMimetype.php

@@ -12,7 +12,7 @@ use Drupal\file\Entity\File;
  * @Condition(
  *   id = "media_source_mimetype",
  *   label = @Translation("Media Source Mimetype"),
- *   context = {
+ *   context_definitions = {
  *     "media" = @ContextDefinition("entity:media", required = FALSE, label = @Translation("Media"))
  *   }
  * )