6 classes are annotated with WorkflowType in Drupal 10

ComplexTestType in core/modules/workflows/tests/modules/workflow_type_test/src/Plugin/WorkflowType/ComplexTestType.php

Test workflow type.

ContentModeration in core/modules/content_moderation/src/Plugin/WorkflowType/ContentModeration.php

Attaches workflows to content entity types and their bundles.

PredefinedStatesWorkflowTestType in core/modules/workflows/tests/modules/workflow_type_test/src/Plugin/WorkflowType/PredefinedStatesWorkflowTestType.php

Test workflow type.

RequiredStateTestType in core/modules/workflows/tests/modules/workflow_type_test/src/Plugin/WorkflowType/RequiredStateTestType.php

Test workflow type.

TestType in core/modules/workflows/tests/modules/workflow_type_test/src/Plugin/WorkflowType/TestType.php

Test workflow type.

WorkflowCustomAccessType in core/modules/workflows/tests/modules/workflow_type_test/src/Plugin/WorkflowType/WorkflowCustomAccessType.php

A test workflow with custom state/transition access rules applied.