Prevent console toggling input from being interpreted twice

[mieldepoche]

This is required since for each frame, _input might run several times (if you have several input events, such as moving the mouse and clicking it at the same time). As a result, just checking the global state with Input.is_action_just_pressed will return true for both events and will show and hide the console in the same frame. (see godotengine/godot#80158 (comment))

(to check that it's a problem, you can move the mouse continually and try toggling the console: you'll notice it sometimes doesn't show up)

[Ark2000]

Good to know it, thanks for your pr!