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
this action plays games under fast-chess with a `debug=yes` compiled binary.
It checks for triggered asserts in the code, or generally for engine disconnects.
closes https://github.com/official-stockfish/Stockfish/pull/5403
No functional change