### 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)

ERR_PRINT(vformat("No valid tile in Tileset for: tile:%s coords:%s flip_h:%s flip_v:%s transpose:%s", v, Vector2i(coord_x, coord_y), flip_h, flip_v, transpose));
				}
			} else {
				int compatibility_alternative_tile = ((int)flip_h) + ((int)flip_v << 1) + ((int)transpose << 2);
				set_cell(Vector2i(x, y), v, Vector2i(coord_x, coord_y), compatibility_alternative_tile);
			}
#endif
		}
	}
}
Vector<int> TileMapLayer::get_tile_data() const {
	
	Vector<int> tile_data;
	tile_data.resize(tile_map.size() * 3);
	int *w = tile_data.ptrw();
	
	int idx = 0;
	for (const KeyValue<Vector2i, CellData> &E : tile_map) {
		uint8_t *ptr = (uint8_t *)&w[idx];
		encode_uint16((int16_t)(E.key.x), &ptr[0]);
		encode_uint16((int16_t)(E.key.y), &ptr[2]);
		encode_uint16(E.value.cell.source_id, &ptr[4]);
		encode_uint16(E.value.cell.coord_x, &ptr[6]);
		encode_uint16(E.value.cell.coord_y, &ptr[8]);
		encode_uint16(E.value.cell.alternative_tile, &ptr[10]);
		idx += 3;
	}
	return tile_data;
}
void TileMapLayer::notify_tile_map_change(DirtyFlags p_what) {