“Select All Custom Attributes” in the Blackboard selects only the Custom Attributes that are in view and does not select Custom Attributes when they are not in view

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 VFX Graph (Assets > Create > Visual Effects > Visual Effect Graph)
4. Open the newly created VFX Graph
5. Create ~8 attributes in the Blackboard by clicking the "+" button
6. Make sure not all of the attributes are in the view by scrolling the Blackboard
7. Right-click the "Custom Attributes" folder and select "Select All Custom Attributes"
8. Observe the selected Custom Attributes

Actual results: The Custom Attributes that were not in view are not selected

Expected results: All Custom Attributes are selected

Reproducible with versions: 6000.0.73f1, 6000.3.14f1, 6000.4.4f1, 6000.5.0b5, 6000.6.0a3

Can’t test with versions: 2023.1.0a3 (due to no “Select All Custom Attributes” functionality)

Tested on (OS): MacOS Silicon Tahoe 26.3, Ubuntu 24.04