10 files declare their use of Registry in Drupal 9

CommentViewBuilder.php in core/modules/comment/src/CommentViewBuilder.php

EntityViewBuilder.php in core/lib/Drupal/Core/Entity/EntityViewBuilder.php

FeedViewBuilder.php in core/modules/aggregator/src/FeedViewBuilder.php

RegistryLegacyTest.php in core/tests/Drupal/Tests/Core/Theme/RegistryLegacyTest.php

RegistryLegacyTest.php in core/tests/Drupal/KernelTests/Core/Theme/RegistryLegacyTest.php

RegistryTest.php in core/tests/Drupal/Tests/Core/Theme/RegistryTest.php

RegistryTest.php in core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php

Stable9TemplateOverrideTest.php in core/tests/Drupal/KernelTests/Core/Theme/Stable9TemplateOverrideTest.php

StableTemplateOverrideTest.php in core/tests/Drupal/KernelTests/Core/Theme/StableTemplateOverrideTest.php

ThemeRegistryLoader.php in core/lib/Drupal/Core/Template/Loader/ThemeRegistryLoader.php