Visual artifacts/shader glitches with default aircraft

Summary

Visual artifacts are appearing on the Cessna 172P on the latest builds of 2024.1.1. This somehow appears to be a regression as it was not occurring on previous 2024.1.1 release candidates. This issue was first identified as part of fgmeta#22 (comment 2351999735), and this is a dedicated issue for it.

Steps to reproduce

1. Download the CI build output for your platform of choice from https://gitlab.com/flightgear/fgmeta/-/pipelines/1672053676
2. Ensure you have deleted your ~/.fgfs directory (or equivalent)
3. Let the installer download the base package
4. Start FlightGear with the C172P, using --log-level=debug
5. Observe the black squares and other artifacts (that also turn white when looked at from behind)
   1. You may need to auto-start the aircraft to trigger the bug

What is the current bug behavior?

Black or white square and other shapes are appearing, presumably where textures or lights should be. There are shader errors in the console.

(Notably, the error reporting dialog does not appear, indicating that that fix was successful)

What is the expected correct behavior?

No visual artifacts on the aircraft or shader errors.

Relevant logs and/or screenshots

https://gitlab.com/-/project/179587/uploads/790a8a5ea55dd75ebaf21c8b60f336f9/fgfs.log

   39.27 [WARN]:general    Error:error-type-bad-data from error-missing-shader::Shader program errors: error: unresolved reference to function `filter_combined'


Shader sources:
	/home/joshua/.fgfs/fgdata_2024_1/Shaders/light-ALS.vert
	/home/joshua/.fgfs/fgdata_2024_1/Shaders/light-ALS.frag
	/home/joshua/.fgfs/fgdata_2024_1/Shaders/noise.frag
	/home/joshua/.fgfs/fgdata_2024_1/Shaders/hazes.frag

System and version information

Using the build from fgmeta!17 (closed), Appimage from this pipeline: https://gitlab.com/flightgear/fgmeta/-/pipelines/1672053676

Fedora Linux 41

/sim/version/flightgear: 2024.1.1
/sim/version/simgear: 2024.1.1
/sim/version/openscenegraph: 3.6.5
/sim/version/build-id: none
/sim/version/build-number: 0
/sim/version/build-type: Release
/sim/version/revision: none
/sim/rendering/gl-vendor: AMD
/sim/rendering/gl-renderer: AMD Radeon RX 5700 XT (radeonsi, navi10, LLVM 19.1.7, DRM 3.59, 6.12.13-200.fc41.x86_64)
/sim/rendering/gl-version: 4.6 (Compatibility Profile) Mesa 24.3.4
/sim/rendering/gl-shading-language-version: 4.60
/sim/rendering/max-texture-size: 16384
/sim/rendering/depth-buffer-bits: 24

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)