TileSet's set_occlusion_layer_light_mask method doesn't work in 4.2 (worked in 4.1.1)

[c-boyle]

Tested versions

• First reproducible in: v4.2.dev5.official [e3e2528]
• Reproducible in: v4.2.stable.official [46dc277], v4.2.dev5.official [e3e2528], v4.2.dev6.official [57a6813]
• Not reproducible in: v4.1.3.stable.official [f06b6836a], v4.2.dev1.official [0c2144d], v4.2.dev2.official [da81ca6], v4.2.dev3.official [013e8e3], v4.2.dev4.official [549fcce]

System information

Godot v4.2.stable - Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1080 (NVIDIA; 31.0.15.4617) - Intel(R) Core(TM) i5-8600K CPU @ 3.60GHz (6 Threads)

Issue description

The TileSet set_occlusion_layer_light_mask method does not properly update the TileSet's light mask, causing shadows to still be cast by the TileSet even when the light mask is changed using the method to a mask different from a given light source (or even an empty light mask). In v4.1.3.stable.official [f06b6836a] this method was working properly.

Steps to reproduce

• Download and open the MRPSetOcclusionLayerTileSet_4.2-stable project folder using one of the reproducible Godot versions noted above.
• Run the project, and press the spacebar key. This will toggle the occlusion layer light mask value of the on-screen TileMap's TileSet occlusion light mask between 0 and 1. You will see that the TileMap still casts shadows regardless of the new value of its TileSets's occlusion layer light mask.

Minimal reproduction project (MRP)

MRPSetOcclusionLayerTileSetBug.zip

[c-boyle]

I believe this is related to #85766

[akien-mga]

PRs merged in 4.2-dev5 which could be related:

• Add per-tile flipping and transposing #80144
• Improve TileMap performances by using quadrants only for rendering #81070