Rename Runner model and API maintainer_note field to maintenance_note
Based on the discussion in gitlab-runner!3268 (comment 815663628) it emerged that the new
maintainer_note field name (also released in a REST API in %14.7 through !77779 (merged)) was not a good name for several reasons, namely because 'maintainer' is the name of a role, which does not necessarily need to match the role in which this field is used, and there is already an instance of a
maintainer_note in our code which is related to the
Create an alias in the
Accept the new
maintenance_notefield in the REST API in addition to
maintenance_notefield in the REST API as deprecated.