[MC-155043] Game output/log gets spammed with 'Fetching packet for removed entity ...' warnings

The bug

After summoning a wither, several Fetching packet for removed entity ... warnings appear in the game output/log.

How to reproduce

Summon a wither:
```
/summon wither
```
Wait some time until the wither destroyed some entities
Watch the game output
→ Notice several Fetching packet for removed entity ... warnings have been thrown

Note

This also appears to happen randomly with no apparent reason. The reproduction method as described in the ticket here is just a way to trigger these warnings.

Game output

[14:59:49] [Server thread/WARN]: Fetching packet for removed entity ats['Slimeball'/25549, l='New World', x=-20.46, y=4.00, z=170.63]
[14:59:53] [Server thread/WARN]: Fetching packet for removed entity ats['Air'/25605, l='New World', x=-9.53, y=2.65, z=152.35]
[14:59:57] [Server thread/WARN]: Fetching packet for removed entity ats['Slimeball'/25656, l='New World', x=-31.92, y=4.00, z=152.25]
[14:59:57] [Server thread/WARN]: Fetching packet for removed entity ats['Wither Rose'/25657, l='New World', x=-31.92, y=4.00, z=152.25]
[15:00:30] [Server thread/WARN]: Fetching packet for removed entity ats['Wither Rose'/26286, l='New World', x=-42.30, y=5.18, z=162.29]
[15:00:35] [Server thread/WARN]: Fetching packet for removed entity ats['Slimeball'/26315, l='New World', x=-9.78, y=4.75, z=160.38]
[15:04:47] [Server thread/WARN]: Fetching packet for removed entity ats['Air'/28764, l='New World', x=-56.45, y=2.54, z=116.62]
[15:04:47] [Server thread/WARN]: Fetching packet for removed entity ats['Air'/28765, l='New World', x=-57.52, y=2.58, z=116.56]
[15:05:37] [Server thread/WARN]: Fetching packet for removed entity ats['Slimeball'/29500, l='New World', x=-69.49, y=4.00, z=95.78]
[15:05:45] [Server thread/WARN]: Fetching packet for removed entity ats['Slimeball'/29662, l='New World', x=-73.14, y=4.00, z=97.44]
[15:05:45] [Server thread/WARN]: Fetching packet for removed entity ats['Wither Rose'/29663, l='New World', x=-73.14, y=4.00, z=97.44]
[15:06:06] [Server thread/WARN]: Fetching packet for removed entity ats['Slimeball'/29970, l='New World', x=-48.47, y=5.00, z=86.67]

[15:20:26] [Server thread/WARN]: Fetching addPacket for removed entity
[15:20:26] [Server thread/WARN]: Fetching addPacket for removed entity
[15:20:46] [Server thread/WARN]: Fetching addPacket for removed entity
[15:20:48] [Server thread/WARN]: Fetching addPacket for removed entity