Weird shadows on specific camera rotation degrees

### Tested versions

Godot 4.3 stable, Godot 4.3 rc3

### System information

Windows 11 - Godot v4.3.stable - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3060ti (552.12 game ready driver) - AMD Ryzen 5 5600X CPU @ 4.00GHz (12 Threads)

### Issue description

I built a simple level with plane as a floor and cube as an object, added omni light and enabled shadows. I noticed, that when camera rotation is set about -90 degress, shadows become weird. If I rotate camera a few degress left or right, shadows become normal, but if I return camera rotation back to about -90 degrees, shadows become weird again.

### Steps to reproduce

Start MRP project
Using keyboard arrows rotate camera. (By default rotation degrees of camera is set to -90, weird shadow changes can be seen if the camera rotates a few degrees to the left or right)

### Minimal reproduction project (MRP)

[weird_shadows_MRP.zip](https://github.com/user-attachments/files/16635288/weird_shadows.zip)

Start by opening and running the linked weird_shadows_MRP.zip with Godot 4.3 on the reported Vulkan setup. Use the keyboard arrows to rotate the camera around -90 degrees and compare the omni light's shadows with nearby rotations. Done means the reproduction no longer shows the reported shadow changes at that angle, with the behavior checked against the minimal project.

Written by the indexing model from the issue text.