There is code released 28 month ago that needs to be removed.

• qiskit/circuit/bit.py:63 (register)
• qiskit/circuit/bit.py:85 (index)

This includes:

• Remove deprecated code and tests (if they only check the deprecation raise)
• tag the PR as Changelog: Removal
• create a release note in the category upgrade:. If you can include an example with an alternative for user to migrate to the new code, as this change might break users code.