Embedded game window disappears with height <= 100

### Tested versions

Any 4.4 since embedded Game window functionality added.

### System information

Godot v4.4.rc3 - Windows 10 (build 19045) - Multi-window, 1 monitor - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3070 (NVIDIA; 32.0.15.6614) - AMD Ryzen 5 5600X 6-Core Processor (12 threads)

### Issue description

When embedded Game window height is smaller then 100px, window disappears. The same happens with floating Game Workspace.
Also if height of panel where embedded Game window will be placed on run is smaller then 100px, on run window height will be set to 100(101?).

https://github.com/user-attachments/assets/5eac6226-c4de-4817-a817-db295195c826

The easiest fix I see is forcing custom minimum height to 101px on run (and reset it back to custom minimum height = 0 on stop) - or set custom minimum height to 101px permanently (but this could cause other issues like GUI overflow with bottom panels (`Audio` for example) on small screens).

### Steps to reproduce

Run any project with game embedding enabled, open any bottom panel and resize it to set embedded game window height below 101.

### Minimal reproduction project (MRP)

"N/A"

Reproduce this in the Godot editor using the embedded Game window or floating Game Workspace, with a bottom panel resized below 101 px. Start by tracing the embedded-game and bottom-panel sizing entry points; done means the game window remains visible at small heights and panels do not acquire an unwanted permanent minimum height.

Written by the indexing model from the issue text.