Blake Anderson

Fix attribution text width (and font size) calculation [Cairo]

1

`text_extents(attribution)[3]` refers to line height, not line width, e.g. `cairo.TextExtents(x_bearing=0.0, y_bearing=-18.0, width=252.0, height=27.0, x_advance=252.0, y_advance=0.0)` changed `[3]` to `.width`, though `[2]` would do the same