Game Locks up and steals mouse in Linux/X11

### Tested versions

v4.2.1.stable.mono.flathub [b09f793f5]

### System information

Godot v4.2.1.stable.mono (b09f793f5) - Freedesktop SDK 23.08 (Flatpak runtime) - X11 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4060 Ti () - AMD Ryzen 7 5700X 8-Core Processor (16 Threads)

### Issue description

When game starts, and I input a direction to move, the game locks up. Produces unref: BUG error messages

### Steps to reproduce

When the game locks up, which in testing so far only happens when inputting a WASD movement. When the game locks up, it won't release the mouse, even if I ALT-TAB into other windows.

The only way to free the mouse and the game is to kill the session from a terminal window. Unfortunately this means I don't have any stack information to provide, I do however have the debugger output, which produces errors I have never seen. I am attaching a screen shot of those errors. Clicking on any of the unref: BUG errors does NOT bring the caret to erroneous code like other errors do. Looking into the Godot sources, this looks like an error capture specifically related strings in X11.

I could attach a copy of the game, however it rely on 3 servers and you wouldn't be able to get the game to run without the servers.

I can work with whoever picks the ticket up to demonstrate or otherwise poke around.


### Minimal reproduction project (MRP)

Not Available

No source file, test, stack trace, or minimal reproduction is provided. Start by reproducing the WASD-triggered lockup on Godot 4.2.1 under Linux/X11 and inspect the attached debugger output; done means the game no longer locks up or retains the mouse, with a reproducible test or regression evidence.

Written by the indexing model from the issue text.