### Godot version

v4.0.3.stable.mono.official [5222a99f5]

### System information

macOS Monterey 12.6.6 (21G646)

### Issue description

When creating a tileset by code with custom data layers, removing a layer with `remove_custom_data_layer` does not update the name-to-layer mapping; `get_custom_data_layer_by_name` will continue to return that layer's original index.

This has a downstream effect of causing TileData objects attempting to use `get_custom_data('Layer B')` to return invalid data (whatever custom data is now in Layer B's old index; e.g. Layer C).

I would expect that after using `remove_custom_data_layer`, I would be able to still use `get_custom_data_layer_by_name` on that tileset.

### Steps to reproduce

Run this code to see that getting Layer B by name after removing the first layer continues to return its original index (1) when in reality it is now at index 0.
```
	var tileset:TileSet = TileSet.new()

	tileset.add_custom_data_layer()
	tileset.set_custom_data_layer_name(0, 'Layer A')
	tileset.set_custom_data_layer_type(0, TYPE_INT)

	tileset.add_custom_data_layer()
	tileset.set_custom_data_layer_name(1, 'Layer B')
	tileset.set_custom_data_layer_type(1, TYPE_STRING)

	print('Layer index 0 name : ', tileset.get_custom_data_layer_name(0)) # Layer A
	print('Layer index 1 name : ', tileset.get_custom_data_layer_name(1)) # Layer B
	print('Layer B is on index : ', tileset.get_custom_data_layer_by_name("Layer B")) # 1

	print('----- removing custom data layer 0 -----')
	tileset.remove_custom_data_layer(0)

	print('Layer index 0 name : ', tileset.get_custom_data_layer_name(0)) # Layer B
	print('Layer index 1 name : ', tileset.get_custom_data_layer_name(1)) # prints an error, as expected
	print('Layer B is on index : ', tileset.get_custom_data_layer_by_name("Layer B")) # returns 1 still! should return 0.
```

### Minimal reproduction project

[RemoveCustomDataLayer.zip](https://github.com/godotengine/godot/files/11804762/RemoveCustomDataLayer.zip)

key_array.push_back(flip_h);
					key_array.push_back(flip_v);
					key_array.push_back(transpose);
					Array value_array;
					value_array.push_back(source_id);
					value_array.push_back(coords);
					value_array.push_back(alternative_tile);
					if (!compatibility_tilemap_mapping.has(E.key)) {
						compatibility_tilemap_mapping[E.key] = RBMap<Array, Array>();
					}
					compatibility_tilemap_mapping[E.key][key_array] = value_array;
					compatibility_tilemap_mapping_tile_modes[E.key] = COMPATIBILITY_TILE_MODE_SINGLE_TILE;
					TileData *tile_data = atlas_source->get_tile_data(coords, alternative_tile);
					tile_data->set_flip_h(flip_h);
					tile_data->set_flip_v(flip_v);
					tile_data->set_transpose(transpose);
					tile_data->set_material(ctd->material);
					tile_data->set_modulate(ctd->modulate);
					tile_data->set_z_index(ctd->z_index);
					if (ctd->occluder.is_valid()) {
						if (get_occlusion_layers_count() < 1) {
							add_occlusion_layer();
						};
						Ref<OccluderPolygon2D> occluder = ctd->occluder->duplicate();
						Vector<Vector2> polygon = ctd->occluder->get_polygon();
						for (int index = 0; index < polygon.size(); index++) {
							polygon.write[index] = xform.xform(polygon[index] - ctd->region.get_size() / 2.0);
						}
						occluder->set_polygon(polygon);
						tile_data->set_occluder(0, occluder);