### Tested versions

- First reproducible in: v4.2.dev5.official [e3e2528ba]
- Reproducible in: v4.2.stable.official [46dc27791], v4.2.dev5.official [e3e2528ba], v4.2.dev6.official [57a6813bb]
- Not reproducible in: v4.1.3.stable.official [f06b6836a], v4.2.dev1.official [0c2144da9], v4.2.dev2.official [da81ca62a], v4.2.dev3.official [013e8e3af], v4.2.dev4.official [549fcce5f]

### 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](https://github.com/godotengine/godot/files/13592741/MRPSetOcclusionLayerTileSetBug.zip)

ret = Vector2(ret.x / 2, ret.y * 2 + ret.x);
					break;
				case TileSet::TILE_LAYOUT_DIAMOND_RIGHT:
					ret = Vector2((ret.x + ret.y) / 2, ret.y - ret.x);
					break;
				case TileSet::TILE_LAYOUT_DIAMOND_DOWN:
					ret = Vector2((ret.x - ret.y) / 2, ret.y + ret.x);
					break;
			}
		} else { 
			switch (tile_set->get_tile_layout()) {
				case TileSet::TILE_LAYOUT_STACKED:
					ret = Vector2(ret.x, ret.y + (Math::posmod(ret.x, 2) == 0 ? 0.0 : 0.5));
					break;
				case TileSet::TILE_LAYOUT_STACKED_OFFSET:
					ret = Vector2(ret.x, ret.y + (Math::posmod(ret.x, 2) == 1 ? 0.0 : 0.5));
					break;
				case TileSet::TILE_LAYOUT_STAIRS_RIGHT:
					ret = Vector2(ret.x * 2 + ret.y, ret.y / 2);
					break;
				case TileSet::TILE_LAYOUT_STAIRS_DOWN:
					ret = Vector2(ret.x, ret.y + ret.x / 2);
					break;
				case TileSet::TILE_LAYOUT_DIAMOND_RIGHT:
					ret = Vector2(ret.x + ret.y, (ret.y - ret.x) / 2);
					break;
				case TileSet::TILE_LAYOUT_DIAMOND_DOWN:
					ret = Vector2(ret.x - ret.y, (ret.y + ret.x) / 2);
					break;
			}