"Add Scene to Scenes in Build" pop-up reappears after Scene has already been added and another Multiplayer Editor Instance is loaded

Steps to reproduce:

1. Create a new project using Universal 3D template
2. Go to Window > Multiplayer > Multiplayer Center
3. Set the "Genre of your Game" to "Adventure" and Players to "2" (or any other options)
4. Click "Install Packages"
5. In the Quickstart tab, click "Create and open scene with netcode setup"
6. Enter Play mode in "NGO_Setup" scene
7. Observe the "Add Scene to Scenes in Build" pop-up opens
8. Click "Yes" and observe the Scene gets added to Build Profiles
9. Open the Multiplayer Play Mode window (Window > Multiplayer > Multiplayer Play Mode) and enable "Player 2"
10. Once opened observe the opened pop-up again

Actual results: The "Add Scene to Scenes in Build" pop-up appears again when the virtual player instance initializes, even though the user already added it to the Build Profiles in step 8

Expected results: The warning popup should only appear once per scene and not pop-up twice

Reproducible with versions: 2.0.1, 2.0.2 (6000.3.12f1, 6000.4.1f1, 6000.5.0b1, 6000.6.0a1)

Tested on (OS): macOS 26.3

Notes:

• On some streams the Build Profile is not created automatically and the window is empty; therefore, it needs to be added manually so the scene can be added. This can be highly problematic and could be handled better if the project has no Build Profiles initially