Remove deprecated metadata in managed package

[jongpie]

Currently, the managed package still contains some old metadata that has been deprecated - this is because previously, there was not a way to remove metadata in a 2GP managed package, unless you had joined a pilot program (I did not do so). The Spring '22 release now has this functionality as GA, so the old metadata should be removed as part of the v4.7.0 - Spring '22 Release milestone.