Removes a few Bitboards and functions that are not used #1767

Job	Run time
Binaries	0s
ARM_Binaries	0s
Prerelease	0s
Compiles / Ubuntu 20.04 GCC	1m 54s
Compiles / Ubuntu 20.04 Clang	2m 41s
Compiles / MacOS 13 Apple Clang	1m 49s
Compiles / MacOS 13 GCC 11	2m 40s
Compiles / Windows 2022 Mingw-w64 GCC x86_64	4m 22s
Compiles / Windows 2022 Mingw-w64 Clang x86_64	3m 57s
Sanitizers / Run with thread sanitizer	3m 33s
Sanitizers / Run with UB sanitizer	1m 33s
Sanitizers / Run under valgrind	3m 0s
Sanitizers / Run under valgrind-thread	3m 28s
Tests / Ubuntu 20.04 GCC	16m 13s
Tests / Ubuntu 20.04 Clang	19m 19s
Tests / Android NDK aarch64	3m 2s
Tests / Android NDK arm	7m 9s
Tests / MacOS 13 Apple Clang	5m 6s
Tests / MacOS 13 GCC 11	5m 51s
Tests / Windows 2022 Mingw-w64 GCC x86_64	10m 35s
Tests / Windows 2022 Mingw-w64 GCC i686	12m 34s
Tests / Windows 2022 Mingw-w64 Clang x86_64	13m 3s
	2h 1m 49s

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