dev.knotless.cancel

Kept in the account of the repository's owner, keyed `<repo key>.<tid>`. A runner acts on the requests in the owner's account, newer than the last it acted on, and on no one else's: it cancels its runs of the ref or the pull going or waiting for their turn when it reads the request, even those of a workflow whose runs finish, and files their checks as cancelled. A merge queue's batches are not a ref's runs. Naming neither a ref nor a pull asks for nothing. With a workflow, only that workflow's runs are cancelled.