Re-fix renderers outliving underlying streams.

e.g. `figure(layout="constrained"); imshow([[0, 1]], rasterized=True); savefig("/tmp/test.pdf")`

src/mplcairo/base.py

@@ -286,7 +286,8 @@ def _print_vector(self, renderer_factory,
                     self.figure.draw(renderer)
             except Exception as exc:
                 draw_raises_done = type(exc).__name__ == "Done"
-                raise
+                if not draw_raises_done:  # Else, will be re-raised below.
+                    raise
             finally:
                 # _finish() corresponds finalize() in Matplotlib's PDF and SVG
                 # backends; it is inlined in Matplotlib's PS backend.  It must
@@ -302,7 +303,7 @@ def _print_vector(self, renderer_factory,
         if draw_raises_done:
             renderer = renderer_factory(None, *self.figure.bbox.size, dpi)
             with _LOCK:
-                self.figure.draw(renderer)
+                self.figure.draw(renderer)  # Should raise Done().
 
     print_pdf = partialmethod(
         _print_vector, GraphicsContextRendererCairo._for_pdf_output)