Expose animation_clip paths (#9392)

Need this for a custom `AnimationPlayer` that I tick in `FixedUpdate`

# Objective

- Need access to an animation clip's `paths` from outside the module

## Solution

- Add a getter method to return a reference to `paths`

---------

Co-authored-by: Tristan Guichaoua <33934311+tguichaoua@users.noreply.github.com>

crates/bevy_animation/src/lib.rs

@@ -102,6 +102,12 @@ impl AnimationClip {
         self.duration
     }
 
+    /// The bone ids mapped by their [`EntityPath`].
+    #[inline]
+    pub fn paths(&self) -> &HashMap<EntityPath, usize> {
+        &self.paths
+    }
+
     /// Add a [`VariableCurve`] to an [`EntityPath`].
     pub fn add_curve_to_path(&mut self, path: EntityPath, curve: VariableCurve) {
         // Update the duration of the animation by this curve duration if it's longer