VideoStream calls wrong virtual function on `set_paused`

[rsubtil]

Godot version

4.1.dev (latest)

System information

Arch Linux

Issue description

cc @kidrigger

With #62737, the set_paused method is not calling the correct virtual function:

godot/scene/resources/video_stream.cpp

Lines 77 to 79 in 8a9af36

	void VideoStreamPlayback::set_paused(bool p_paused) {
	GDVIRTUAL_CALL(_is_playing, p_paused);
	}

This ends up not being much of an issue because the video player internally stops processing the playback when paused, but I think this is currently wrong nevertheless.

Steps to reproduce

• Develop a GDExtension addon adding new video playback options (like https://github.com/kidrigger/godot-video-reference/tree/canon).
• Define your own _set_paused method.
• This method is not called by the engine.

Minimal reproduction project

N/A - Not viable