Prevent User Delete, Reassign Content to Anonymous

The only purpose of this module is to remove the "Delete the account and make its content belong to the Anonymous user" (user_cancel_reassign) option from appearing on the User Cancellation Form (/user/{user}/cancel) and the Bulk User Cancellation Form (/admin/people/cancel).

There is an open core bug, #2977362: Revision user incorrectly appears as anonymous user when node author is cancelled, that comes up when using this option. Additionally, we are seeing a critical issue where old revisions created by the deleted user are being republished as the default version of a node. Given the severity of this issue, we've created this extremely simple module to remove that option.