### 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)

HashMap<Vector2i, TileSet::TerrainsPattern> terrain_fill_constraints(const Vector<Vector2i> &p_to_replace, int p_terrain_set, const RBSet<TerrainConstraint> &p_constraints); 
	HashMap<Vector2i, TileSet::TerrainsPattern> terrain_fill_connect(const Vector<Vector2i> &p_coords_array, int p_terrain_set, int p_terrain, bool p_ignore_empty_terrains = true); 
	HashMap<Vector2i, TileSet::TerrainsPattern> terrain_fill_path(const Vector<Vector2i> &p_coords_array, int p_terrain_set, int p_terrain, bool p_ignore_empty_terrains = true); 
	HashMap<Vector2i, TileSet::TerrainsPattern> terrain_fill_pattern(const Vector<Vector2i> &p_coords_array, int p_terrain_set, TileSet::TerrainsPattern p_terrains_pattern, bool p_ignore_empty_terrains = true); 
	
	TileMapCell get_cell(const Vector2i &p_coords, bool p_use_proxies = false) const;
	
	void set_tile_data(DataFormat p_format, const Vector<int> &p_data);
	Vector<int> get_tile_data() const;
	void notify_tile_map_change(DirtyFlags p_what);
	void internal_update();
	
	
	void set_cell(const Vector2i &p_coords, int p_source_id = TileSet::INVALID_SOURCE, const Vector2i p_atlas_coords = TileSetSource::INVALID_ATLAS_COORDS, int p_alternative_tile = 0);
	void erase_cell(const Vector2i &p_coords);
	int get_cell_source_id(const Vector2i &p_coords, bool p_use_proxies = false) const;
	Vector2i get_cell_atlas_coords(const Vector2i &p_coords, bool p_use_proxies = false) const;
	int get_cell_alternative_tile(const Vector2i &p_coords, bool p_use_proxies = false) const;
	TileData *get_cell_tile_data(const Vector2i &p_coords, bool p_use_proxies = false) const; 
	void clear();
	
	Ref<TileMapPattern> get_pattern(TypedArray<Vector2i> p_coords_array);
	void set_pattern(const Vector2i &p_position, const Ref<TileMapPattern> p_pattern);
	
	void set_cells_terrain_connect(TypedArray<Vector2i> p_cells, int p_terrain_set, int p_terrain, bool p_ignore_empty_terrains = true);
	void set_cells_terrain_path(TypedArray<Vector2i> p_path, int p_terrain_set, int p_terrain, bool p_ignore_empty_terrains = true);
	
	TypedArray<Vector2i> get_used_cells() const;
	TypedArray<Vector2i> get_used_cells_by_id(int p_source_id = TileSet::INVALID_SOURCE, const Vector2i p_atlas_coords = TileSetSource::INVALID_ATLAS_COORDS, int p_alternative_tile = TileSetSource::INVALID_TILE_ALTERNATIVE) const;