Move system updates to the same patch system as members

PluralKit.Core/Models/ModelQueryExt.cs

@@ -28,16 +28,5 @@ namespace PluralKit.Core
             conn.QueryFirstAsync<MemberGuildSettings>(
                 "insert into member_guild (guild, member) values (@guild, @member) on conflict (guild, member) do update set guild = @guild, member = @member returning *",
                 new {guild, member});
-
-        public static Task<PKMember> UpdateMember(this IPKConnection conn, MemberId id, MemberPatch patch)
-        {
-            var (query, pms) = patch.Apply(new UpdateQueryBuilder("members", "id = @id"))
-                .WithConstant("id", id)
-                .Build("returning *");
-            return conn.QueryFirstAsync<PKMember>(query, pms);
-        }
-
-        public static Task DeleteMember(this IPKConnection conn, MemberId id) =>
-            conn.ExecuteAsync("delete from members where id = @Id", new {Id = id});
     }
 }