do not upload some unneeded intermediate directories, disable running authenticated git commands with the checkout action. Thanks to Yaron A for the report. closes https://github.com/official-stockfish/Stockfish/pull/5435 No functional change
verifies that all mate PVs printed for finished iterations (i.e. no lower or upper bounds), are complete, i.e. of the expected length and ending in mate, and do not contain drawing or illegal moves. based on a set of 2000 positions and the code in https://github.com/vondele/matetrack closes https://github.com/official-stockfish/Stockfish/pull/5390 No functional change