Cell.write_svg has incorrect type annotation for shape_style

[FaustinCarter]

The type annotation for shape_style is dict[tuple[int, int], str] | None. However, based on the example in the documentation here (https://heitzmann.github.io/gdstk/library/gdstk.Cell.html#gdstk.Cell.write_svg) it should actually be dict[tuple[int, int], dict[str, str]] | None.

[heitzmann]

Thanks for reporting!