unregister provider for unused "Class Reference Provider" key
unregister provider for unused "Class Reference Provider" key

GitOrigin-RevId: 7944877836978a53d6caca12919f47d16c506f95
allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community,allotria/intellij-community