Fixing ChessPlay.java for 1.18 --> 1.20

[riri404]

Errors found:

• [x] error: level has private access in Entity
• [x] error: incompatible types: possible lossy conversion from double to int

[riri404]

• changed .level to .level() which might return null

• Casted in to the Double variable, I didnt want to change the data types of the variables in case it misses something up