Screen reader slowdown

### Tested versions

4.5 dev 1 and later

### System information

Windows 11

### Issue description

When using NVDA with Godot I have found the experience degrades rather quickly. My NVDA slows down a lot as I use Godot. I have tried re-starting NVDA or Navigating away and back to the Godot window but it does not seem to fix the issue.
I'm not sure why this would be happening but the only thing that seems to fix it is closing and re-opening Godot. I'm sure there is probably a buffer of accessibility events or something that gets full but I can't say.

### Steps to reproduce

1. turn on NVDA,
2. Open Godot,
3. Navigate around a bit e.g. open a project and tab around,
4. Notice NVDA will slowly take longer and longer to respond

### Minimal reproduction project (MRP)

N/A