Cleanup after fake ponder hit removal

src/Lynx/Engine.cs

@@ -2,8 +2,6 @@
 using Lynx.UCI.Commands.Engine;
 using Lynx.UCI.Commands.GUI;
 using NLog;
-using System.Diagnostics;
-using System.Security.Cryptography;
 using System.Threading.Channels;
 
 namespace Lynx;
@@ -87,14 +85,7 @@ public void NewGame()
             }
         }
 
-        // Clear killer moves
-        Debug.Assert(_killerMoves.Length == 3);
-        Array.Clear(_killerMoves[0]);
-        Array.Clear(_killerMoves[1]);
-        Array.Clear(_killerMoves[2]);
-        // No need to clear _previousKillerMoves
-
-        // _pVTable will be cleared on IDDFS, since it needs to be cleaned for every search as well, no matter what
+        // No need to clear killer move or pv table because they're cleared on every search (IDDFS)
     }
 
     public void AdjustPosition(ReadOnlySpan<char> rawPositionCommand)

src/Lynx/Search/IDDFS.cs

@@ -40,12 +40,6 @@ public sealed partial class Engine
     private bool _isScoringPV;
 
     private SearchResult? _previousSearchResult;
-    private readonly int[][] _previousKillerMoves =
-    [
-        new int[Configuration.EngineSettings.MaxDepth],
-        new int[Configuration.EngineSettings.MaxDepth],
-        new int[Configuration.EngineSettings.MaxDepth]
-    ];
 
     private readonly Move _defaultMove = default;
 
@@ -151,8 +145,6 @@ public sealed partial class Engine
                 lastSearchResult = UpdateLastSearchResult(lastSearchResult, bestEvaluation, alpha, beta, depth, isMateDetected, bestEvaluationAbs);
 
                 await _engineWriter.WriteAsync(InfoCommand.SearchResultInfo(lastSearchResult));
-
-                Array.Copy(_killerMoves, _previousKillerMoves, _killerMoves.Length);
             } while (StopSearchCondition(++depth, maxDepth, isMateDetected, decisionTime));
         }
         catch (OperationCanceledException)