⚖️ Incremental eval - bishop pair

[eduherminio]

Test  | eval/incremental-bishop-pair
Elo   | -2.01 +- 3.20 (95%)
SPRT  | 8.0+0.08s Threads=1 Hash=32MB
LLR   | -2.25 (-2.25, 2.89) [0.00, 3.00]
Games | 20046: +5601 -5717 =8728
Penta | [528, 2384, 4306, 2286, 519]
https://openbench.lynx-chess.com/test/1210/

Test  | eval/incremental-bishop-pair
Elo   | 0.64 +- 1.97 (95%)
SPRT  | 40.0+0.40s Threads=1 Hash=128MB
LLR   | -0.44 (-2.25, 2.89) [0.00, 3.00]
Games | 42198: +10717 -10639 =20842
Penta | [597, 5006, 9851, 5012, 633]
https://openbench.lynx-chess.com/test/1232/