10 files declare their use of QueryBase in Drupal 9

ConditionAggregate.php in core/lib/Drupal/Core/Entity/Query/Sql/ConditionAggregate.php

PgsqlQueryFactory.php in core/modules/workspaces/src/EntityQuery/PgsqlQueryFactory.php

Query.php in core/lib/Drupal/Core/Config/Entity/Query/Query.php

Query.php in core/lib/Drupal/Core/Entity/KeyValueStore/Query/Query.php

Query.php in core/lib/Drupal/Core/Entity/Query/Sql/Query.php

Query.php in core/lib/Drupal/Core/Entity/Query/Null/Query.php

QueryFactory.php in core/modules/workspaces/src/EntityQuery/QueryFactory.php

QueryFactory.php in core/lib/Drupal/Core/Config/Entity/Query/QueryFactory.php

QueryFactory.php in core/lib/Drupal/Core/Entity/Query/Sql/QueryFactory.php

QueryFactory.php in core/lib/Drupal/Core/Entity/Query/Null/QueryFactory.php