Remove tune.h

[winapiadmin]

tune.h was used for tuning HCE, but since Stockfish 16.1 HCE was removed, and the codebase no longer uses the header anymore.

[locutus2]

@winapiadmin That is not correct. The tune files are used for tuning any parameter like search or time management. The last commit of stockfish are the result of tuning using this files.

Here this final commit 7fe46b5

And here the SPSA tuning run for this https://tests.stockfishchess.org/tests/view/68a07826fd8719b088c8dc23