[REQ] Support Mill Build Tool #22651
Description
Mill is a Scala build tool which can also be used for Java, Kotlin and experimentally for Python, Typescript, Groovy. Its approach is at a sweet spot between Maven (purely declarative) and Gradle (programmable with a lot of plugin magic) since instead of plugins it just relies on tasks and simple libraries. Configuration is done via Scala code or Yaml.
Currently there is only a partial implementation of Openapitools options available in a community project.
Users usually refer to the official tooling for build tool integration, hence providing a official plugin (in Mill just a library module) would make it easy for user to get the support they need.