Error when stopping AnimationPlayer without current animation.

[pmoosi]

Tested versions

Reproducible in 4.4 after #91765

System information

Godot v4.4.dev.mono (8c16e67) - Ubuntu 24.04.1 LTS 24.04 on Wayland - X11 display driver, Multi-window, 3 monitors - Vulkan (Forward+) - integrated AMD Radeon Graphics (RADV RENOIR) - AMD Ryzen 7 5800H with Radeon Graphics (16 threads)

Issue description

Calling AnimationPlayer.Stop() when no animation is running results in

E 0:00:00:0349   anim_stop.gd:4 @ _ready(): AnimationPlayer has no current animation.
  <C++ Error>    Parameter "playback.current.from" is null.
  <C++ Source>   scene/animation/animation_player.cpp:737 @ get_section_start_time()
  <Stack Trace>  anim_stop.gd:4 @ _ready()

It looks like the bug was introduced by #91765.

Steps to reproduce

Create a scene with an animation player and call stop().

Minimal reproduction project (MRP)

mrp.zip