Remove deprecated user.set_root_password method (#14140)

We don't currently consume this endpoint and have already marked
it as deprecated. Remove it completely to eliminate an endpoint
that allows unauthenticated access.

src/middlewared/middlewared/plugins/account.py

@@ -1193,21 +1193,6 @@ async def has_local_administrator_set_up(self):
         """
         return len(await self.middleware.call('privilege.local_administrators')) > 0
 
-    @no_auth_required
-    @accepts(
-        Password('password'),
-        Dict('options')
-    )
-    @returns()
-    @pass_app()
-    async def set_root_password(self, app, password, options):
-        """
-        Deprecated method. Use `user.setup_local_administrator`
-        """
-        warnings.warn("`user.set_root_password` has been deprecated. Use `user.setup_local_administrator`",
-                      DeprecationWarning)
-        return await self.setup_local_administrator(app, 'root', password, options)
-
     @no_auth_required
     @accepts(
         Str('username', enum=['root', 'truenas_admin']),