### 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)

tile_lines_mesh->add_surface_from_arrays(Mesh::PRIMITIVE_LINE_STRIP, a, Array(), Dictionary(), Mesh::ARRAY_FLAG_USE_2D_VERTICES);
		tile_meshes_dirty = false;
	}
	if (p_filled) {
		p_canvas_item->draw_mesh(tile_filled_mesh, p_texture, p_transform, p_color);
	} else {
		p_canvas_item->draw_mesh(tile_lines_mesh, Ref<Texture2D>(), p_transform, p_color);
	}
}
Vector<Point2> TileSet::get_terrain_polygon(int p_terrain_set) {
	if (tile_shape == TileSet::TILE_SHAPE_SQUARE) {
		return _get_square_terrain_polygon(tile_size);
	} else if (tile_shape == TileSet::TILE_SHAPE_ISOMETRIC) {
		return _get_isometric_terrain_polygon(tile_size);
	} else {
		float overlap = 0.0;
		switch (tile_shape) {
			case TileSet::TILE_SHAPE_HEXAGON:
				overlap = 0.25;
				break;
			case TileSet::TILE_SHAPE_HALF_OFFSET_SQUARE:
				overlap = 0.0;
				break;
			default:
				break;
		}
		return _get_half_offset_terrain_polygon(tile_size, overlap, tile_offset_axis);
	}
}
Vector<Point2> TileSet::get_terrain_peering_bit_polygon(int p_terrain_set, TileSet::CellNeighbor p_bit) {