Crash when adding or removing animation from Blender

[Hilderin]

Tested versions

Reproductible in 4.3 rc2
Reproductible in 4.3 master

System information

Godot v4.3.rc2 - Windows 10.0.22631 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3060 (NVIDIA; 32.0.15.6070) - 11th Gen Intel(R) Core(TM) i5-11600KF @ 3.90GHz (12 Threads)

Issue description

When adding or removing an animation in a .blend file, when reimporting, Godot crashes.
Adding does not causes the problem every time, but removing causes the problem almost every time.

One example of the crash when removing an animation:

A second example when removing:

A example when adding an animation:

A second example when adding an animation:

Demonstration:

blender_0Q1rlNR1FU.mp4

Steps to reproduce

When removing animations:

• Create 2 animations in Blender
• Import blender file in Godot
• Remove one animation in Blender (from the Blender File > Actions), save
• Go back to the editor
• The animation is still there or the editor will crash

When adding animations:

• Create a new animation in Blender
• Import blender file in Godot
• Add a new animation in Blender (from the Blender File > Actions), save
• Go back to the editor
• The editor will crash

EDITED: The problem seems to happen only when the "Editable children" is enabled. Probably related, when reopening the scene, I got these warnings:

scene\resources\packed_scene.cpp:254 - Node 'TestModel/metarig' was modified from inside an instance, but it has vanished.
scene\resources\packed_scene.cpp:179 - Parent path './TestModel/metarig' for node 'Skeleton3D' has vanished when instantiating: 'res://TestScene.tscn'.
scene\resources\packed_scene.cpp:254 - Node './Skeleton3D' was modified from inside an instance, but it has vanished.

Minimal reproduction project (MRP)

test-godot-import-animation-blender.zip