Remove wgArticleRobotPolicies

* testwiki page has been deleted
* enwiki pages both have user-added __NOINDEX__
* rowiki page entries don't seem to be working. To fix this we should use __NOINDEX__ on the pages rather than changing anything here

Bug: 48478
Change-Id: Ib32078737b8663e25ca569b8b902da2c37c4c084