Error "_load_from_cache: Condition "br != variant_size" is true. Returning: false" on console when turning SDFGI on

### Tested versions

- Reproducible on v4.4.1.stable.official [49a5bc7b6]

### System information

Windows 11 - Vulkan 1.4.303 - Forward+ - Using Device #0: NVIDIA - NVIDIA GeForce GTX 1650

### Issue description

On a simple scene with a mix of CSG and regular meshes with textures applied, a directional light and a WorldEnvironment with custom color background, turning SDFGI on causes the error below to appear on console. Turning SDFGI off fixes the issue.

E 0:00:01:057 _load_from_cache: Condition "br != variant_size" is true. Returning: false
servers/rendering/renderer_rd/shader_rd.cpp:477 @ _load_from_cache()

### Steps to reproduce

- Open the MRP
- On the "root" scene, select the WorldEnvironment node and turn on SDFGI. No other settings are needed
- Run the project
- Error should appear on console
- Stop the project and turn off SDFGI, then run it again
- Error won't appear

### Minimal reproduction project (MRP)

MRP with scene already set up.

https://github.com/Dancovich/3d-environment-lighting-example

Start at servers/rendering/renderer_rd/shader_rd.cpp:477 and reproduce the issue with the linked minimal project. Compare console output with SDFGI enabled and disabled, then verify that running the reproduced scene with SDFGI enabled no longer emits the _load_from_cache error.

Written by the indexing model from the issue text.