Multiplayer Play Mode Scenarios Panel Can Be Resized Beyond Usable Limit

Steps to reproduce:

1.  Create a new Unity Project
2.  Install the Multiplayer Play Mode package from the Package Manager
3.  Navigate to Window > Multiplayer > Play Mode Scenarios
4.  Use the middle resizer bar to resize the scenario section horizontally
5.  Observe the layout behaviour

Actual results: The panel can be resized to the edge, effectively collapsing it and making it hard to interact with or resize again

Expected results: The panel should have a minimum horizontal size, preventing it from being resized beyond a usable limit

Reproducible with versions: 1.5.0-exp.2 (6000.0.47f1, 6000.1.0f1, 6000.2.0a9)

Not reproducible with versions: 2022.3.61f1 (No "Multiplayer Center" window is unavailable)

Tested on (OS): macOS 15.5 (Silicon M4)

Notes:
* The absence of a minimum size makes it difficult to return the panel to its original state, affecting usability