### 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)

TypedArray<Vector2i> a;
	for (const KeyValue<Vector2i, CellData> &E : tile_map) {
		const TileMapCell &c = E.value.cell;
		if (c.source_id == TileSet::INVALID_SOURCE) {
			continue;
		}
		a.push_back(E.key);
	}
	return a;
}
TypedArray<Vector2i> TileMapLayer::get_used_cells_by_id(int p_source_id, const Vector2i p_atlas_coords, int p_alternative_tile) const {
	
	TypedArray<Vector2i> a;
	for (const KeyValue<Vector2i, CellData> &E : tile_map) {
		const TileMapCell &c = E.value.cell;
		if (c.source_id == TileSet::INVALID_SOURCE) {
			continue;
		}
		if ((p_source_id == TileSet::INVALID_SOURCE || p_source_id == c.source_id) &&
				(p_atlas_coords == TileSetSource::INVALID_ATLAS_COORDS || p_atlas_coords == c.get_atlas_coords()) &&
				(p_alternative_tile == TileSetSource::INVALID_TILE_ALTERNATIVE || p_alternative_tile == c.alternative_tile)) {
			a.push_back(E.key);
		}
	}
	return a;
}
Rect2i TileMapLayer::get_used_rect() const {