6 files declare their use of LocalActionDefault in Zircon Profile 8.0

BlockContentAddLocalAction.php in core/modules/block_content/src/Plugin/Menu/LocalAction/BlockContentAddLocalAction.php

Contains \Drupal\block_content\Plugin\Menu\LocalAction\BlockContentAddLocalAction.

LocalActionDefaultTest.php in core/tests/Drupal/Tests/Core/Menu/LocalActionDefaultTest.php

Contains \Drupal\Tests\Core\Menu\LocalActionDefaultTest.

MenuLinkAdd.php in core/modules/menu_ui/src/Plugin/Menu/LocalAction/MenuLinkAdd.php

Contains \Drupal\menu_ui\Plugin\Menu\LocalAction\MenuLinkAdd.

TestLocalAction.php in core/modules/system/tests/modules/menu_test/src/Plugin/Menu/LocalAction/TestLocalAction.php

Contains \Drupal\menu_test\Plugin\Menu\LocalAction\TestLocalAction.

TestLocalAction4.php in core/modules/system/tests/modules/menu_test/src/Plugin/Menu/LocalAction/TestLocalAction4.php

Contains \Drupal\menu_test\Plugin\Menu\LocalAction\TestLocalAction4.

TestLocalAction5.php in core/modules/system/tests/modules/menu_test/src/Plugin/Menu/LocalAction/TestLocalAction5.php

Contains \Drupal\menu_test\Plugin\Menu\LocalAction\TestLocalAction5.