Graph Toolkit dirty graphs are not prompted to save when closing the Editor with a clean graph focused

Steps to reproduce:

1. Create and open a new project
2. Import the [Internal link] script into the project
3. Create "Assets/Create/Graph Toolkit Samples/Simple Graph"
4. Duplicate it and open both files in the Editor
5. Create a variable in one graph (to make it dirty)
6. Focus on the other graph tab
7. Close the Editor

Actual results: Editor closes without a prompt

Expected results: Prompt to save the changes pops up

Reproducible with versions: 6000.3.0a1 (0.1.0-exp.1) 6000.3.22f1, 6000.5.8f1, 6000.6.0b8, 6000.7.0a5

Tested on (OS): Windows 11 Pro (25H2)

Notes:

• Changes are lost upon closing the Editor
• The graphs don't have to be docked on the same panel