Skip emit warn if has equivalent onXXX prop

Editor assessment

feat(runtime-core) says the emit warning is skipped when an equivalent onXXX prop exists. The scope and feature type fit, the subject is imperative and unterminated, and no footer is needed. No body explains the false positive the change suppresses or the prop-name matching rule, so a reader must infer the motivation. Understandable and correctly scoped, it is publishable with only a modest context gap noted.