7 files declare their use of SchemaObjectExistsException in Drupal 9

DatabaseStorage.php in core/lib/Drupal/Core/KeyValueStore/DatabaseStorage.php

DbImportCommand.php in core/lib/Drupal/Core/Command/DbImportCommand.php

Schema.php in core/lib/Drupal/Core/Database/Driver/sqlite/Schema.php

Schema.php in core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php

Schema.php in core/lib/Drupal/Core/Database/Driver/mysql/Schema.php

SchemaTest.php in core/tests/Drupal/KernelTests/Core/Database/SchemaTest.php

UserCreationTrait.php in core/modules/user/tests/src/Traits/UserCreationTrait.php