Editing Blend Position under AnimationTree's inspector doesn't automatically update the crosshair position within the BlendSpace1D editor

### Tested versions

Reproducible in 4.6.dev2

### System information

Godot v4.6.dev2 - Windows 11 (build 22631) - Multi-window, 2 monitors - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4090 Laptop GPU (NVIDIA; 32.0.15.8129) - 13th Gen Intel(R) Core(TM) i9-13900HX (32 threads) - 63.81 GiB memory

### Issue description

Editing the Blend Position from within the Inspector doesn't automatically update the AnimationTree Editor within the tab. This can be a little confusing when glancing at it without clicking into it, I would have expected it to automatically update after changing the Blend Position.

### Steps to reproduce

1. Add a blendspace1d to an Animationtree node

2. Click on the pencil icon to edit the BlendSpace1D

3. Type something into the Blend Position and you'll notice that the BlendSpace1D UI does not change unless you click into it manually.

### Minimal reproduction project (MRP)

N/A

Reproduce the issue through the AnimationTree inspector and the BlendSpace1D editor using the listed steps, then trace how editing Blend Position refreshes the editor view. Confirm that changing the inspector value updates the crosshair without requiring a manual click, and verify the behavior again in the same setup.

Written by the indexing model from the issue text.