### Godot version

4.01

### System information

Windows 10

### Issue description

It seems a tiles Custom Data is cleared/not set when "Local to Scene" is enabled for the TileMap in the Resource section. At least the custom data isn't set by the time of the _ready function in the script attached to the TileMap.

### Steps to reproduce

create TileMap and tileset with custom data and attached script. in _ready method attempt to read custom data from a used cell. 

In Attached project run it. It will print_debug if it found custom data or not. "Local to Scene" is enabled so it will not find the custom data.

### Minimal reproduction project

[TileMapCustomDataLocalBugReproduce.zip](https://github.com/godotengine/godot/files/11470771/TileMapCustomDataLocalBugReproduce.zip)

if (p_name == "tile_data") {
		r_ret = _get_tile_data();
		return true;
	}
	return false;
}
void TileMapPattern::_get_property_list(List<PropertyInfo> *p_list) const {
	p_list->push_back(PropertyInfo(Variant::OBJECT, "tile_data", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL));
}
void TileMapPattern::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_cell", "coords", "source_id", "atlas_coords", "alternative_tile"), &TileMapPattern::set_cell, DEFVAL(TileSet::INVALID_SOURCE), DEFVAL(TileSetSource::INVALID_ATLAS_COORDS), DEFVAL(TileSetSource::INVALID_TILE_ALTERNATIVE));
	ClassDB::bind_method(D_METHOD("has_cell", "coords"), &TileMapPattern::has_cell);
	ClassDB::bind_method(D_METHOD("remove_cell", "coords", "update_size"), &TileMapPattern::remove_cell);
	ClassDB::bind_method(D_METHOD("get_cell_source_id", "coords"), &TileMapPattern::get_cell_source_id);
	ClassDB::bind_method(D_METHOD("get_cell_atlas_coords", "coords"), &TileMapPattern::get_cell_atlas_coords);
	ClassDB::bind_method(D_METHOD("get_cell_alternative_tile", "coords"), &TileMapPattern::get_cell_alternative_tile);
	ClassDB::bind_method(D_METHOD("get_used_cells"), &TileMapPattern::get_used_cells);
	ClassDB::bind_method(D_METHOD("get_size"), &TileMapPattern::get_size);
	ClassDB::bind_method(D_METHOD("set_size", "size"), &TileMapPattern::set_size);
	ClassDB::bind_method(D_METHOD("is_empty"), &TileMapPattern::is_empty);
}
bool TileSet::TerrainsPattern::is_valid() const {
	return valid;
}
bool TileSet::TerrainsPattern::is_erase_pattern() const {
	return not_empty_terrains_count == 0;
}
bool TileSet::TerrainsPattern::operator<(const TerrainsPattern &p_terrains_pattern) const {