Consider to remove sorting at MeterIdPrefix

Currently, we sort the micrometer tags at MeterIdPrefix to create Meter ID stably. https://github.com/line/armeria/blob/master/core/src/main/java/com/linecorp/armeria/common/metric/MeterIdPrefix.java#L95-L101

Since I saw this stacktrace from our service’s flamegraph, I would like to consider whether it is avoidable or not. Since it doesn’t have many samples, we can be ignored but because it is not optimal, it would be happy if we can avoid this sort.