Chore

Upkeep that changes no capability — documentation, build scripts, tooling, dependency updates, refactoring, moving to a supported runtime.

A chore may be large, and it may well affect the release. That is not a contradiction: the type says why the work exists, and how much rigour it carries is a separate question answered by what it touches.

Test: after this, can anyone do something they could not do before? If no, it is a chore.