Getlegalmoves nonalloc

[eduherminio]

I must be messing something up, search is super slow with this change

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Edit.

Spolier: I was

See https://github.com/lynx-chess/Lynx/pull/301/files

        Array.Sort(moves, (moveA, moveB) =>
        {
            var scoreA = ScoreMove(moveA, ply, true, bestMoveTTCandidate);
            var scoreB = ScoreMove(moveB, ply, true, bestMoveTTCandidate);

            return scoreA == scoreB ? 0 : (scoreA > scoreB ? -1 : 1);
        });