Updated SettingsPanel

Removed Close button, and code associated with it, as we are switching
from in-viewport Panels, to Popup Windows.

UI/settings_panel.gd

@@ -1,12 +1,5 @@
 extends PanelContainer
 
-@onready var close_panel: Button = %ClosePanel
-
 # Called when the node enters the scene tree for the first time.
 func _ready() -> void:
-	close_panel.pressed.connect(_handle_close_panel)
-	pass # Replace with function body.
-
-func _handle_close_panel() -> void:
-	Globals.enable_mouse_passthrough()
-	queue_free()
+	pass