### 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)

Transform2D xform;
							xform = flip_h ? xform.scaled(Size2(-1, 1)) : xform;
							xform = flip_v ? xform.scaled(Size2(1, -1)) : xform;
							xform = transpose ? Transform2D(xform[1], xform[0], Vector2()) : xform;
							int alternative_tile = 0;
							if (!atlas_source->has_tile(coords)) {
								atlas_source->create_tile(coords);
							} else {
								alternative_tile = atlas_source->create_alternative_tile(coords);
							}
							
							Array key_array;
							key_array.push_back(coords);
							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_ATLAS_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);