chore: 删除无用的项目配置和资源文件修改android key,修正godot4.3无法构建的问题

- 移除 .gitattributes 和 .gitignore 文件
- 删除 Asserts 目录下的棋盘和棋子基础资源文件

Scripts/Utilities/VirtualBoard.cs

@@ -1,74 +0,0 @@
-// using System.Numerics;
-using Godot;
-using System;
-
-public class VirtualBoard {
-    private readonly int Rows;
-	private readonly int Cols;
-	private readonly VirtualPiece[,] pieces;
-
-    // <oldPiece, newPiece>
-    public event Action<VirtualPiece, VirtualPiece> OnSetPiecePos;
-    public event Action<VirtualPiece> OnInsert;
-    public event Action<VirtualPiece> OnRemove;
-    public event Action<Vector2, Vector2> OnMove;
-
-	public VirtualBoard(int Rows, int Cols) {
-		this.Rows = Rows;
-		this.Cols = Cols;
-		pieces = new VirtualPiece[Rows, Cols];
-	}
-
-	public bool ArrPosOutOfRange(Vector2 arrayPos) {
-		return arrayPos.X < 0 || arrayPos.X >= Rows || arrayPos.Y < 0 || arrayPos.Y >= Cols;
-	}
-
-    public VirtualPiece GetPiece(Vector2 arrayPos) {
-		if (ArrPosOutOfRange(arrayPos)) return null;
-        return pieces[(int)arrayPos.X, (int)arrayPos.Y];
-    }
-
-    public VirtualPiece SetPiecePos(VirtualPiece piece, Vector2 arrayPos) {
-		VirtualPiece ret = null;
-		if (ArrPosOutOfRange(arrayPos)) return ret;
-        ret = pieces[(int)arrayPos.X, (int)arrayPos.Y];
-		pieces[(int)arrayPos.X, (int)arrayPos.Y] = piece;
-        OnSetPiecePos?.Invoke(ret, piece);
-		piece?.Move(arrayPos);
-		return ret;
-    }
-
-    public bool InsertPiece(VirtualPiece piece, Vector2 arrayPos) {
-        if (GetPiece(arrayPos) != null) {
-            return false;
-        }
-        OnInsert?.Invoke(piece);
-		SetPiecePos(piece, arrayPos);
-        return true;
-	}
-
-	public bool MovePiece(Vector2 from, Vector2 to) {
-		if (ArrPosOutOfRange(to) || ArrPosOutOfRange(from)) {
-			return false;
-		}
-		if (GetPiece(to) != null) {
-			return false;
-		}
-        OnMove?.Invoke(from, to);
-        SetPiecePos(SetPiecePos(null, from), to);
-		return true;
-	}
-
-	public bool RemovePiece(Vector2 pos) {
-        OnRemove?.Invoke(GetPiece(pos));
-		return SetPiecePos(null, pos) != null;
-	}
-
-	public void Clear() {
-		for (int i = 0; i < Rows; i++) {
-			for (int j = 0; j < Cols; j++) {
-				RemovePiece(new Vector2(i, j));
-			}
-		}
-	}
-}