Switching between tabs in the editor causes flickering between tab contents

### Tested versions

- Reproducible in 4.3.rc1, 4.2.2.stable and 4.1.4.stable. Have not tested any earlier versions yet.

### System information

Godot v4.3.rc1 - Arch Linux #1 ZEN SMP PREEMPT_DYNAMIC Fri, 28 Jun 2024 04:32:27 +0000 - Wayland - Vulkan (Forward+) - dedicated NVIDIA GeForce GT 730M (nvidia; 470.256.02) - Intel(R) Core(TM) i5-4300M CPU @ 2.60GHz (4 Threads)

### Issue description

When I switch between tabs, like the Scene and Import tabs, or the different scenes in the editor, then the view for the content that the tab represents starts flickering back and forth between the previous tab and new one. It also sometimes causes other elements of the UI to flicker as well. When I move my cursor off of the tabs then the flickering subsides.

https://github.com/user-attachments/assets/d1912217-abc1-49ac-a71b-2f477d251d76

https://github.com/user-attachments/assets/a569fcb2-60ca-4392-aa9a-9eee49c7616f

### Steps to reproduce

The bug is visible in new projects.

### Minimal reproduction project (MRP)

N/A

Start by reproducing the flicker when switching Scene, Import, or scene tabs in a new project, using the reported Godot versions and Wayland/Vulkan environment if available. Inspect the editor tab-switching path and compare the displayed contents while the cursor is over and away from the tabs. Done means switching tabs no longer flickers between old and new contents or other UI elements.

Written by the indexing model from the issue text.