### 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)

polygon = _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;
				}
				polygon = _get_half_offset_terrain_polygon(tile_size, overlap, tile_offset_axis);
			}
			{
				Ref<ArrayMesh> mesh;
				mesh.instantiate();
				Vector<Vector2> uvs;
				uvs.resize(polygon.size());
				Vector<Color> colors;
				colors.resize(polygon.size());
				colors.fill(Color(1.0, 1.0, 1.0, 1.0));
				Array a;
				a.resize(Mesh::ARRAY_MAX);
				a[Mesh::ARRAY_VERTEX] = polygon;
				a[Mesh::ARRAY_TEX_UV] = uvs;
				a[Mesh::ARRAY_COLOR] = colors;
				a[Mesh::ARRAY_INDEX] = Geometry2D::triangulate_polygon(polygon);
				mesh->add_surface_from_arrays(Mesh::PRIMITIVE_TRIANGLES, a, Array(), Dictionary(), Mesh::ARRAY_FLAG_USE_2D_VERTICES);