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

Main.tscn

@@ -1,50 +0,0 @@
-[gd_scene load_steps=3 format=3 uid="uid://boa4od72355o4"]
-
-[ext_resource type="Script" path="res://Main.cs" id="1_h4cv2"]
-[ext_resource type="Theme" uid="uid://intlbeu8h82r" path="res://Asserts/defaultTheme.tres" id="2_afihr"]
-
-[node name="Main" type="Node2D"]
-script = ExtResource("1_h4cv2")
-
-[node name="Control" type="Control" parent="."]
-layout_mode = 3
-anchors_preset = 0
-theme = ExtResource("2_afihr")
-
-[node name="SignlePlayer" type="Button" parent="Control"]
-layout_mode = 0
-offset_left = 83.0
-offset_top = 671.0
-offset_right = 298.0
-offset_bottom = 850.0
-text = "单人"
-
-[node name="MultiPlayer" type="Button" parent="Control"]
-layout_mode = 0
-offset_left = 406.0
-offset_top = 670.0
-offset_right = 612.0
-offset_bottom = 852.0
-text = "多人"
-
-[node name="Label" type="Label" parent="Control"]
-layout_mode = 0
-offset_left = 191.0
-offset_top = 265.0
-offset_right = 501.0
-offset_bottom = 451.0
-theme_override_font_sizes/font_size = 48
-text = "中国象棋"
-horizontal_alignment = 1
-vertical_alignment = 1
-
-[node name="Setting" type="Button" parent="Control"]
-layout_mode = 0
-offset_left = 239.0
-offset_top = 967.0
-offset_right = 450.0
-offset_bottom = 1150.0
-text = "设置"
-
-[connection signal="pressed" from="Control/SignlePlayer" to="." method="GoToSignlePlayer"]
-[connection signal="pressed" from="Control/MultiPlayer" to="." method="GoToMultiPlayer"]