Update default net to nn-46832cfbead3.nnue

[SFisGOD]

SPSA 1: https://tests.stockfishchess.org/tests/view/6100e7f096b86d98abf6a832
Parameters: A total of 256 net weights and 8 net biases were tuned (output layer)
Base net: nn-56a5f1c4173a.nnue
New net: nn-ec3c8e029926.nnue

SPSA 2: https://tests.stockfishchess.org/tests/view/610733caafad2da4f4ae3da7
Parameters: A total of 256 net biases were tuned (hidden layer 2)
Base net: nn-ec3c8e029926.nnue
New net: nn-46832cfbead3.nnue

STC:
LLR: 2.98 (-2.94,2.94) <-0.50,2.50>
Total: 50520 W: 3953 L: 3765 D: 42802
Ptnml(0-2): 138, 3063, 18678, 3235, 146
https://tests.stockfishchess.org/tests/view/610a79692a8a49ac5be793f4

LTC:
LLR: 2.94 (-2.94,2.94) <0.50,3.50>
Total: 57256 W: 1723 L: 1566 D: 53967
Ptnml(0-2): 12, 1442, 25568, 1589, 17
https://tests.stockfishchess.org/tests/view/610ac5bb2a8a49ac5be79434

Closes #3642

Bench: 5023636

[SFisGOD]

@vondele Could you please commit these books? official-stockfish/books#19 official-stockfish/books#20