AnimationTree fails resolving track on node with unique name (%)

### Tested versions

4.3.dev.custom build master today

### System information

window10 gd4.3.dev.custom build

### Issue description

scene\animation\animation_mixer.cpp:663 - AnimationMixer: 'anim/unarmed-swim-idle', couldn't resolve track: '%GeneralSkeleton:RightUpperLeg'. This warning can be disabled in Project Settings. (User)



To make this node reusable by multiple different model scenes, I made it a separate scene and set an empty skeleton and animationplayer with %naming, the animationplayer loads external animation lib so it can be used for animation tree node editing

However, this would trigger an error and it takes a long time to load every time.

### Steps to reproduce

create A scene import the glb with animation player,and create a animationtree for it.then save the animation tree as a branch scene.

### Minimal reproduction project (MRP)

1.open player/roles/male_warrior/MaleWarrior.tscn
remove animationtree node
reinstance a RoleAnimationTree scene on it .and see the error

2.open assets/models/male_warrior/male_warrior.glb
select load pose to use external animlib
and select assets/anim.res, see another error(can not pick bindbones animlib.Even man.glb and male_warrior.glb its the same bone map)

Start with scene/animation/animation_mixer.cpp:663 and reproduce the warning using player/roles/male_warrior/MaleWarrior.tscn, RoleAnimationTree, and assets/models/male_warrior/male_warrior.glb. Check the external animation library and unique-name track setup described in the issue. Done means the track resolves without the repeated warning and the external animation library can be selected as described.

Written by the indexing model from the issue text.