### 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)

for (KeyValue<Vector2i, CellData> &kv : tile_map) {
			CellData &cell_data = kv.value;
			_debug_quadrants_update_cell(cell_data, dirty_debug_quadrant_list);
		}
	} else {
		
		for (SelfList<CellData> *cell_data_list_element = dirty.cell_list.first(); cell_data_list_element; cell_data_list_element = cell_data_list_element->next()) {
			CellData &cell_data = *cell_data_list_element->self();
			_debug_quadrants_update_cell(cell_data, dirty_debug_quadrant_list);
		}
	}
	
	for (SelfList<DebugQuadrant> *quadrant_list_element = dirty_debug_quadrant_list.first(); quadrant_list_element;) {
		SelfList<DebugQuadrant> *next_quadrant_list_element = quadrant_list_element->next(); 
		DebugQuadrant &debug_quadrant = *quadrant_list_element->self();
		
		bool has_a_tile = false;
		RID &ci = debug_quadrant.canvas_item;
		for (SelfList<CellData> *cell_data_list_element = debug_quadrant.cells.first(); cell_data_list_element; cell_data_list_element = cell_data_list_element->next()) {
			CellData &cell_data = *cell_data_list_element->self();
			if (cell_data.cell.source_id != TileSet::INVALID_SOURCE) {
				has_a_tile = true;
				break;
			}
		}
		if (has_a_tile) {
			
			if (ci.is_valid()) {
				rs->canvas_item_clear(ci);
			} else {