Fix checksum error boundary in 1.21.9 and 1.21.11.

[TAOtxi]

fix PrismarineJS/node-minecraft-protocol#1488

[extremeheat]

Why is the checksum an i8 and not u8? That almost certainly seems wrong

Come to think of it PrismarineJS/node-minecraft-protocol#1442 doesn't seem to make sense either. Is there some inconsistency?

[TAOtxi]

@extremeheat wiki mentioned checksum is sign byte.

[extremeheat]

Java doesn't have unsigned types. This is not relevant to a checksum which are almost always treated as unsigned. It doesn't make sense to have a signed checksum

[extremeheat]

A 32 bit checksum will use all 32 bits, there is no "sign bit" left over

[extremeheat]

Looks like the root issue is that there are different checksum fields with a mismatch of i8/u8... this should be fixed and nmp PR can be reverted

[TAOtxi]

But https://github.com/PrismarineJS/minecraft-data/blob/master/data/pc/1.21.8/protocol.json#L9045 is also i8, and this commit fix the issue I mentioned.😐

[extremeheat]

Yes, it's incorrectly i8 in some places and u8 in others. Being fixed in #1188 and PrismarineJS/node-minecraft-protocol#1489