7 files declare their use of ConfigEntityBundleBase

BlockContentType.php in core/modules/block_content/src/Entity/BlockContentType.php
CommentType.php in core/modules/comment/src/Entity/CommentType.php
ContactForm.php in core/modules/contact/src/Entity/ContactForm.php
MediaType.php in core/modules/media/src/Entity/MediaType.php
NodeType.php in core/modules/node/src/Entity/NodeType.php
ShortcutSet.php in core/modules/shortcut/src/Entity/ShortcutSet.php
Vocabulary.php in core/modules/taxonomy/src/Entity/Vocabulary.php