fix: add some deadzone for joypad motion detection

Prior to this change, if there was both a keyboard and joypad connected
and the user was using the keyboard, but there was some stick drift with
the joypad, input detection would bounce between keyboard and joypad.

This change adds a minimum axis_value that a InputEventJoypadMotion must
have before being detecting the input type as a joypad.

addons/input_prompts/input_prompt_manager.gd

@@ -98,6 +98,8 @@ func _input(event: InputEvent):
 			icons = InputPrompt.Icons.KEYBOARD
 			emit_signal("icons_changed")
 	if event is InputEventJoypadButton or event is InputEventJoypadMotion:
+		if event is InputEventJoypadMotion and event.axis_value < 0.05:
+			return
 		var device = event.device
 		var joy_name = Input.get_joy_name(device)
 		if joy_name.find("Xbox"):