When renaming a category in the Blackboard the category stays in the same order but when the Graph is saved the category moves/reorders to the bottom

Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Install the Visual Effect Graph package (com.unity.visualeffectgraph)
3. Create a new Visual Effect Graph (Assets > Create > Visual Effects > Visual Effect Graph)
4. Open the newly created Visual Effect Graph
5. Create 3 new Categories by clicking the "+" button in the Blackboard
6. Rename the first Category (top of the list)
7. Observe the Blackboard
8. Save the Visual Effect Graph
9. Repeat step 7

Actual results: RenameCategory removes and re-appends the entry, so the stored order changes. The blackboard keeps the old position until the graph is reopened, then the category jumps to the end. 

Expected results: The Category should instantly jump to the end or it should not be reordered at all

Reproducible with versions: 6000.0.0f1, 6000.0.83f1, 6000.3.24f1, 6000.5.11f1, 6000.6.1f1, 6000.7.0a6

Tested on (OS): MacOS Silicon Tahoe 26.6.2, Ubuntu 24.04

Notes:

• For versions 6000.0.0f1, 6000.0.83f1, 6000.3.24f1, 6000.5.11f1, saving the Graph is not enough, it needs to be reopened to see the reorder
• This is very inconvenient when managing bigger Graphs, especially in streams 6000.5 and below as reopening the Visual Effect Graph completely changes the Blackboard