### 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)

const Ref<TileSet> &tile_set = tile_map_node->get_tileset();
	ERR_FAIL_COND(tile_set.is_null());
	ERR_FAIL_COND(p_pattern.is_null());
	TypedArray<Vector2i> used_cells = p_pattern->get_used_cells();
	for (int i = 0; i < used_cells.size(); i++) {
		Vector2i coords = tile_map_node->map_pattern(p_position, used_cells[i], p_pattern);
		set_cell(coords, p_pattern->get_cell_source_id(used_cells[i]), p_pattern->get_cell_atlas_coords(used_cells[i]), p_pattern->get_cell_alternative_tile(used_cells[i]));
	}
}
void TileMapLayer::set_cells_terrain_connect(TypedArray<Vector2i> p_cells, int p_terrain_set, int p_terrain, bool p_ignore_empty_terrains) {
	const Ref<TileSet> &tile_set = tile_map_node->get_tileset();
	ERR_FAIL_COND(!tile_set.is_valid());
	ERR_FAIL_INDEX(p_terrain_set, tile_set->get_terrain_sets_count());
	Vector<Vector2i> cells_vector;
	HashSet<Vector2i> painted_set;
	for (int i = 0; i < p_cells.size(); i++) {
		cells_vector.push_back(p_cells[i]);
		painted_set.insert(p_cells[i]);
	}
	HashMap<Vector2i, TileSet::TerrainsPattern> terrain_fill_output = terrain_fill_connect(cells_vector, p_terrain_set, p_terrain, p_ignore_empty_terrains);
	for (const KeyValue<Vector2i, TileSet::TerrainsPattern> &kv : terrain_fill_output) {
		if (painted_set.has(kv.key)) {
			
			TileMapCell c = tile_set->get_random_tile_from_terrains_pattern(p_terrain_set, kv.value);
			set_cell(kv.key, c.source_id, c.get_atlas_coords(), c.alternative_tile);
		} else {